Don't schools get funded by local property taxes? More development (the hundreds of apartment blocks) = more property taxes = more funding for the school.s
I do blame the city for being willing to look the other way and enabling it.
It's fairly common for big developers to get temporary tax abatements for developing big projects. I have seen "temporary" over 10 years, and I wouldn't be surprised to learn that sometimes it goes beyond 20.
The OP mentioned Seattle, which apparently has a boilerplate 12-year tax abatement for multi-family developments: https://clarknuber.com/seattles-multifamily-property-tax-exe...
12 years is a long time to underfund municipal services in an area.