It's already an altcoin by definition... alternative cryptocurrency, as is any fork of Bitcoin. So they're just doing the logical thing =)
I think it would be great to Bitcoin if both alt coins fail in less than one month. If this doesn't happen, more people will try fork Bitcoin and claim that they are the real deal.
Bitcoin gold is just a scam. And should be treated this way. Bitcoin 2x is an attack on the core team. This just confuses new users and make all the community look bad.
They won't fail, since they will take any measure of success as objective achieved. Even Bitcoin Cash trading at 6% of Bitcoin value will be considered a success, given Bitcoin's incredible value range now. As long as miners make profit, they'll continue hashing at forks, and they'll keep on trading indefinitely. Regardless of the outcome, the good news is these forks no longer threaten Bitcoin, but strengthen it. BCH already set the precedence, so I foresee more future forks, each with less magnitude of "success".