Biggest isn't always best. National agendas get murky real quickly. If large economies attempt to exert influence over Bitcoin, we're all suddenly along for the ride. Whether the outcome of that is "good" or "bad" remains to be seen. I'd personally rather Bitcoin remain as neutral as possible and remain somewhat separate to the realm of fiat. In my mind, it's a healthy distance at present. All this "mainstream adoption" people seem to be clamouring for could well have consequences depending on the form it takes.
But how does any government entity cause Bitcoin to not be neutral? It still will be an open, permissionless system that's decentralized, no? Plus if yor fears become true, and Bitcoin does become compromised and becomes "not neutral", then Bitcoin is not robust enough and therefore has no reason to exist.
Plus to be truly separate from the "realm of fiat", Bitcoin should have developed a parallel economy where everything is denominated in Bitcoin. The Dark Markets would have been that parallel economy if they were not scamming after a few months of operation.