But it would selectively drive out productive members of community. Adding more rules to an already broken legislation would not work in the long run.

This might well be a good thing to do, but it should be noted that income qualifications come with their own entire bag of tricky problems and potential perverse incentives.

What income level do you set it at? Is it a cliff or phased out? If the latter, what does the curve look like? How does it change with inflation? Are these questions set up front or negotiated by politicians at some frequency? How is wage vs. capital-based income handled? These are the kinds of tricky questions that come up (and are usually not answered very well) with any program that attempts to inject some income-based fairness into some government system.

So I think the answer to your "why not?" is that it will be hard to get it right and is likely to become a political football that may end up making things worse in some way. But the argument for doing it may still be stronger (it seems so to me, without knowing much about it), I'm just saying that there is also a fairly strong counterargument to this sort of thing.

That discourages people from moving up in pay. It'd likely be cheaper to make less money.

You'd also encourage rich people to hide their money. Especially trust fund kids who's income is low as they only take out what they need to spend.

That's the first time I've heard this suggestion but it seems to make a lot of sense

Then homes would simply get deeded only in the name of the stay-at-home spouse who has no income.

Someone with little to no income can still be very wealthy. You're also discouraging people from getting better paying jobs. You also gotta deal with properties deeded in trusts and stuff.

This also makes sense to me.