It may very well be that we would do better to forbid a wider range of contest-like things; see e.g.
puzzling.meta.stackexchange.com/questions/7202/… where some person called bobble proposed dropping condition 3 and some other guy called Gareth McCaughan said "probably a good idea but I think we should probably go further than that" ... and then, er, we didn't take it any further. :-)