This might be controversial, probably not completely fact based, and maybe I'm missing some socioeconomic thing that would flip this argument on its head:
I really don't like 'luxury' apartment buildings.
And I lived in one in the past.
Why? Much of it is personal, I'll admit. But, I really think they're the worst of both worlds for a good chunk of the population they're aimed at. For $1200ish a month, I can get a 2 Bed/ 2 Bath ~900 sq. foot 'luxury' apartment. Many have some sort of garage available, as well as a fitness center and a pool. You don't have to mow the lawn, shovel snow, or change your HVAC filter.
Great? Not in my book. I said they're the worst, and I mean it.
Around me, apartment complexes are basically supplanting the small 2/3 bed, 1.5/2 bath starter homes. So instead of having a small house with a small yard, you get 900 sq. ft. with little storage and little privacy. The former starter homes are either being flipped into luxury boomer retirement homes, or being razed so that a large 'custom home' (or 2 or 3 smaller ones) can be rebuilt on the property.
Where there aren't any apartments being built, there are townhomes that are slapped up and together faster than should be possible. We rent a townhome and have no yard and still little privacy. Nobody has an incentive to renovate these townhouses because they're not well-built and the people in them are not the best neighbors.
The expectation now is that if you're young or single or young and single you move into the apartment complex because it's what you can afford. The people who are living in these apartments, I've found, can't save enough to move out of them because of the 'luxury' label - they're paying too much for what they have, and so they never move out and into the starter homes. This leaves the starter homes to those with plenty of cash to turn them into anything but a starter home.
And so here we are, stuck because our townhome is too small and poorly laid out for our family, but what were starter homes are now going for $250-$300k when 7 or 8 years ago, they were going for $160-$200k.
I'm sure it's good for communities long-term (unless the community doesn't have the septic infrastructure to handle a massive development...) but for people like me, it sure leaves us in a shit situation.
/rant
Perhaps the people who are voting against the apartment complex are ones that don't want to see an influx of young and single people because then "there goes the neighborhood".