The problem is that the benches do nothing but displace the problem. They don't solve anything, but they certainly LOOK like they do, right?

Not really. If the problem is homeless people occupying a bench intended for sitting, such a bench solves that particular problem. If the problem for a shop is that homeless people are occupying the entrance, installing spikes solves that shop's problem, despite there still being a problem of homelessness. It all depends on how meta/focused you approach the "problem".

However, now the buck is just being passed to someone else who doesn't have these "nice" benches.

That is true, however it may not be equally much of a problem if a person is sleeping on a bench in the park, vs on a bench in front of a store. But you are right that the cause is getting passed on.

Furthermore, the homeless are people too, and regardless of how they look and act they should be treated with dignity. And don't think you think if the problem is more visible people are going to be more enthusiastic to solve it? A sad truth about us is that if we don't see it, it probably doesn't exist.

That's true, and I am not particularly against it, but I would not lash out against people using such benches either.

The second argument I didn't address because it's not a great argument to begin with and I didn't agree with it.

Eh.. That they can afford a bench but not a solution to entire poverty seems like a pretty solid argument to me, and more of a fact than something you'd disagree with, but maybe that's just me :P

If I understand what you're saying, that's a shit analogy (pun intended) because installing public toilets actually solves the problem instead of displacing it

Installing toilets = solving poverty, preventing people to sleep on benches while poverty is being solved = forbidding people to shit on the streets while toilets are being installed. But yeah, pointed bollards is another "solution".