Based on the things I've read from gurus over the years, assuming they're being truthful and accurate, I think the general picture I get is:
1) Some of the employees on the sims team are probably in agreement with you on some features (or lack thereof). They just have little to no say in how or when or if it gets implemented.
2) Sometimes a feature is desired, but the people with the most veto power aren't convinced it will sell. For example, some comment Grant made at one point w/ regards to somebody asking about more diverse trash cans. I think the general gist of the comment was that he thought it would be hard to market such a thing. (Not saying people should run with this and assume it about every 'missing' feature; the point is just that it can be a factor.)
3) Sometimes the squeaky wheel gets the grease, as the saying goes. Yeah, it seems like on occasion that the stuff that is brought up most vocally by the community gets attention it may not have otherwise gotten. The sims team is not prescient and I would guess it's hard to keep track of all the different things people want, along with various marketing and sales goals being thrust upon them.
Should they be excused for missing a lot of features people feel are essential? Should people take it for granted that they are listening? That's up to each person. I think it's clear they do some listening, but listening doesn't always mean "doing what you want" either. Listening can also mean "hearing what you have to say and giving it some thought." I can say that in my time as a modder, there have been periods where if I did everything people asked for, I'd never have time to do anything else; which isn't exactly fun for me and I have to consider that sometimes people are going to ask for things that are in direct contradiction to one another, or that sometimes what someone asks for is something that five people will use and find interesting. Then again, sometimes what one person is asking for is something that a huge amount of people are silently wishing for.
Best thing you can probably do as a fan is just voice what is it you're looking for persistently, with some gaps in-between, to give them time to digest it. It sucks to feel like you aren't being heard though. I pretty much always feel that way in one way or another when I'm following a 'live service' game. I think I've just gotten used to it at this point. Which I'm not sure is a good thing, but that's how it is for me.