In this case Art is defined by the tools, prims, sculpties and meshes are all tools, limits would define what people can wear, want to wear your 100 prims hair, your 100 prim jewelry, your 200 prim shoes, you should have to pick and choose or buy premium to raise the limit or god forbid, buy something will less prim usage. If we continue at this rate there wont be a Second Life because Lindens wont be able to afford super servers and thus the SL experience will be a virtual slideshow limited to those with nasa super computers.
You cant say that an artist should have no limits, because when you get right down to it, people in SL are not artists, they are 3D content designers, with 3D constraints. Im not saying that legacy content should be outright broken, but if you want to wear the above said shoes you are going to have to pick and choose or buy new content (which happens all the time btw) with more conservative server weight, like meshes for example.
Like everything, if you dont adapt you get left behind and SL will get left behind, social platforms are in thier infancy, everyone is jumping on the bandwagon and a serious company will come along and do what second life does but loads better (i'm not talking about these amateur copies out there)