This is definitely a good question and I think one of these type of competitors could potentially hurt bitcoin. Though I think most people would not be for a governmental controlled or sponsored coin because one of the major advantages of Bitcoin is the decentralized nature of it. However, if one of these big players does try to put out a competing cryptocurrency it could certainly drive some of the bitcoin users away so it is good to think of how bitcoin would overcome these challenges.
Bitcoin can adapt. If an alt coin did come along that was better or had something unique and interesting bitcoin could very likely implement their code and evolve.
Well, to loosely paraphrase Andreas Antonopoulos:
"There are already hundreds of currencies, so what's a few more? There could be multiple successful cryptocurrencies."
Agreed. It's a free market, but I think we only really need bitcoin to be honest.