I like it. It it were me, I would add a couple of horizontal joiners between some of the vertical legs, also attached to the flat bottom.
The other thing I would consider is placing several well positioned horizontal 2x4s underneath the whole thing, so that the whole thing is slightly raised and so any spillage does not accumulate underneath but instead dryes quickly by ventilation. Otherwise the bottom can begin to rot.
What keeps some of those vertical 2x4's from wobbling around? Any reason you didn't put a piece of plywood on the top of the stand?
Other than that it looks good.