I'm still not sure why you so strongly deprecate the activity of using mesh.
As a creation technology it is the most detailed way to achieve full control over an object's form. There is no copycat issue at stake here. It is a technology broadly used in all applications of graphics, including film, video, architecture, effects, games and more. Finally, (finally!), it has come to Opensim.
I do imagine that you are commenting from the perspective that a certain authenticity will be lost because mesh capability also allows the import of content, no building required. However, given the broad range of purposes people bring to the Opensim platform, I think it makes more sense to give more options and look for authenticity in the results, as well as the means.
If my challenge is to create a learning environment, the goal is teaching. It will be fantastic if I can find lots of pre-made content, as my purpose is to educate, not to build. On the other hand if I'm looking to create an interactive exhibit of automobile prototypes, I may want to build some realistic mesh objects that would be hard or impossible to construct accurately using only prims.
It still seems to me that mesh has a valid place along with prims and sculpted prims in making rich immersive experiences.