Why does everybody hate the idea of multiplayer in TS5?

I wouldn't mind multiplayer as long as it is optional and the game doesn't require a constant internet connection and objects etc are not locked behind multiplayer. Meaning you don't have to explore multiplayer to get access to certain items.

So basically I'd be open for multiplayer as long as I don't have to play if I don't like it. I also believe it might be the "next big thing" they can do for the sims series.
We've had aging with TS2, open world (and colour wheel) with TS3 and emotions (and multitasking) with TS4.

I guess they need to reinvent the series a bit for every iteration to justify you buying the game over the span of years all over again.