Why when I start a completely new game adding lots have used the moved cheat?

This update regarding the gallery was done a while ago... I want to say a couple of years. You have always been able to upload builds to the gallery using Move Objects, it's simply that when downloading them - if you didn't have Move Objects on when you placed the lot - anything out of place would be lost, the same as if you downloaded something with CC (also allowed) or a pack you didn't own.

The way the downloads work now, instead of deleting things that are out of place, it simply lets you know that the build was done with Move Objects, and as such, somethings may be in a place where they technically can't be replaced without the cheat. The downside is that before many (though not everyone) would add a #MOO hashtag to their uploads and now it's easier to forget.

Some people do a lot of work to get a build looking a particular way, and sometimes the game at default won't let you do it. So they use Move Objects on to get it to look right. Heck, I use it a lot because sometimes I think that an item's footprint is ridiculously large, or otherwise doesn't make sense.

I fail to see how this is "forcing" you to play your game in a certian way, however. It's certainly not the game, but the builds you choose to dowload, that use this cheat.

As said by @DaWaterRat this message is merely to tell you that the lot was created with move objects on. It is not forcing you to anything. It just means some items are placed with a cheat to remove restrictions on placement of objects. You can always use a sledge hammer to remove objects you don't want.

I would like to add that there is a huge variety in lots that use the move object on cheat (MOO). Some use MOO for a bit more creativity on lots they intend to be playable, for example place two doors in a corner with overlapping footprint. This can often be seen in the real world and works well in the game. Some however just want to create a pretty build and don't care about gameplay. I once downloaded a very good looking magical shop from the gallery and after half a minute I deleted the lot because it was simply not usable. I would suggest looking for tags like #noMOO (I believe I have seen it on the gallery) to be sure the cheat was not used. Also #playtested is useful because that means the creator tested to build to be functional, even if they used MOO.

I like this particular change because I don't have to enter the move objects on cheat every time I place a lot. But I do get your sentiment about sims 4 constantly adding changes. Most of them are improvements but sometimes all the changes and updates take up so much energy. It feels like the game is in constant development. Sometimes I long for the good old sims 2 days where my game stayed the same unless I actively decided to install a DLC or a patch.

The comparison sounds sort of like older games (that I grew up with, on the Sega Genesis and Nintendo 64, DS and Gameboy etc) were complete when you bought them, whereas now games usually have updates that add new things. Personally I like the updates with most games. I play Animal Crossing New Leaf on my "new" 2ds xl (Nintendo has an interesting way of naming things...), which came completed. However I also play Animal Crossing New Horizons, which had ongoing updates for a few years, and the updates included some very exciting things! I love both games and see the value in both types. I don't believe that a game that receives updates with new things is unfinished, I think that they are just creating new fun content for the players to keep them engaged. I know that is kind of rambling and getting off topic and all this. (I ramble a lot.) I just read a LOT of people complaining about this regarding almost all of the games that I play. I think people have to recognize that games have changed, and that's ok.

I have to say I just ignore the warning. Especially since I don't use MOO in my own builds, and yet this pops up when I'm simply placing one of my own builds to the game. Something is broken and the poster could be correct in their assessment. We've got all kinds of gameplay I wish we didn't have, for instance and I purposefully ignored the purchase of Eco-Living based on the description we would learn a new way to play the game, or words to that effect. No, thank you. I love the whole sandbox notion of play. I didn't begin my Sim-Odyssey until Sims2, which I loved. I take a different stand, however. I don't mind all the add-ons, so much. I've learned to simply pick and choose what I want in my game. Sadly, HSY added some things I'm not so keen on, but hey, it is what it is. Most of it came in the patch, I'll warrant.

I agree with @GalacticGal that the MoveObjects warning when installing some lots from the Gallery is not always correct. I have come across a few lots that give the warning even though the cheat was not used. The same goes for the custom content warning. There are many of those that get slapped with that warning even though it is all EA content… but that is another topic. ?

I'm actually surprised when I place a lot and the warning doesn't come up, because it pretty much always does. And there are lots that I know I didn't use it on. It annoyed me at first, but now I just ignore it. And even though I used to be in the "absolutely not!" camp, I have found myself using it more because there are quite a few decorative objects that have huge footprints now. I am just careful not to use it on anything Sims will interact with.

If there is anything on a downloaded lot that I don't like, I just remove it myself and re-save the lot. I'd be more concerned if CC snuck in since I don't use it at all.

I've wondered if it also notes the use of alt placing when it gives that warning. I alt place alllll the time and while I don't consider that a cheat, it is technically placing items outside their footprints.

I use move objects now sometimes, I just try not to block anything. If you see sims waving their hands around, but not getting to the intended object, it’s probably because someone blocked it by moving an object somewhere they shouldn’t have.

It isn't just buildings from the gallery, but also houses EA has built that the warning pops up on. I play with the offline for gallery, and I use my own, but it still pops up

I've never used 'move objects' in my life in this game and I get the same message when using my own lots for the game. I just ignore it. It might be because I use lots made before the Gallery updates or downloaded someone else's lot that did use it once.