If your point is that this has no direct harmful effect on bitcoin itself, I mostly agree (and disagree with cyperdoc) and consider side chains to be a bitcoin application that leads to more demand for bitcoin (to put in the "vault"), except for possible systemic and contagion effects, which are difficult or impossible to reason about in advance.
I never said there are no direct harmful effects, I only said that the allocation is known, and then pointed out how that itself is a large step better than today.
Good point. I've always said that side chains are a useful tool that likely make bitcoin more powerful and better.