I’m inclined to agree. Lots of avatar creators and asset creators will likely get swamped in support requests or questions from people who purchase their content, due to inevitable issues with the VRCSDK Optimizer breaking these assets.
I think rolling it out as off by default and then reconsidering on by default at a later date would be a more effective move. It’d allow creators to test out the feature and see how it works, and give feedback to VRChat about it.