No, clearly not. Housing isn't a commodity and moving is a pain. If I offered you $10/month in a rent reduction (or off the mortgage if you own) to move across the street to an identical home, would you? How about saving $10/month in return for increasing your commute by 10 minutes a day?
Obviously, both of those become worth it at some level of savings. And decreasing rent by 0.05% to double the units occupied is worth it (probably). But there's a huge overlap in the middle where it's not clear what the effects will be, and that's where the real world is.
It's definitely true that things are more complicated in the real world, but that fact doesn't have-wave us into "Z is non-negative" territory.
That is, not only is Y=X a bad deal, but Y=X+Z is a bad deal for a good deal of positive Zs. Up to Zmax which is a positive value. For all values of Z < Zmax (including negative Zs) it's bad for JPM