Why in the world would Pres Trump be so against a bi-partisan bill that helps working Americans?

Maybe because its just a puff piece of legislation, much like Trump.

FTA: "The legislation can play an important role in encouraging states and localities to make changes to expand housing supply, but it doesn't require them to make those changes," Freemark said. "Congress has chosen not to preempt local and state governments and tell them what to do,"

But is the real reason because he cares little about affordability of working Americans?

This is mind reading and you're bad at it. Not just you but everyone is, so you shouldn't use it. But I see you use mind reading in many of your posts, insinuating others intentions by trying to read their minds, as opposed to relying upon evidence.

Tell me again you're technical, because the evidence is slim to none.

So little that he was willing to stymie the passage of an overwhelmingly bi-partisan affordable housing bill in order to get his voter suppression bill passed?

If the bill doesn't do anything, why shouldn't he leverage it to get what he wants done?

Everyone seems to want the "press" of a bill that does nothing. That is leverage any president would be wise to use to move their own agenda forward.