I agree with OP.
I don't think that "for children" means "childish" though. If we remember TS1, it had strippers. It was easier to die, you had more control, the needs were harder to maintain and there was higher risk of a fire, higher risk of drowning, of being electrocuted, etc etc. TS4 is very much an utopia sort of simulator where everyone's happy all the time, there is no drama, there are no scancalds, there is barely any lore, sims don't have deep background stories. That's what I think of when I think of "for children". Everything is easier and the game lacks depth, because children (and I'm generalizing now) don't care about reading up on backstories or investigating scandals and hidden secrets of families.
It also ties into details, because details means more work. TS2 had personality points, horoscopes and turn-offs and turn-ons. TS3 had favorites (favorite food, color, music). These are the things that would make TS4 feel more "adult" for me, because there are more details and more things for the player to control. It's the simplification of gameplay and game mechanics that makes TS4 seem more "for children".
When I say I'd prefer it to be a bit more "adult" I don't mean that I want to install 18+ mods with violence and s*xual content. I just mean I want more depth. Bring me some actual challenge, I don't want a life simulator to be "perfect" where everyone gets what they want and I have to actively make an effort to create and pretend that my sims have drama in their lives, because that's not an actual life simulator. TS4 is an utopia simulator with no challenge, no risks, no drama, no mess, no hardships, and you barely have to put in any effort to succeed.
That's my personal opinion and argument of why TS4 is "for children" rather "for adults".
