I agree the height restrictions should be more generous, but we shouldn't go to the other extreme. A minimum isn't necessary: property developers will build as much as they think will turn any profit whatsoever. You don't need to force them to try to make money -- just get out of there way!
There's also a downside to minimums: 10-story buildings aren't very cheap to build (unlike 5-story buildings), causing problems if you want new housing stock to target the poor and working class. This makes it challenging to build on the urban fringe where 3-story buildings should be replacing single family homes. 10-story buildings have no business out there, unless maybe you're building next to a transit hub.
You can try to define the "core" part of the city that needs 10-story buildings, but this is more micromanaging than you need to be, and the law will need to keep up with a changing urban landscape. As we've seen in SF and many other US cities, that's a tall order.