"Today on the Sourceforge hosted Bitcoin-development mailing list Gavin Andresen has threatened to leave his present group of Bitcoin software developers over their objections to his demands for a rapid hardfork of the Bitcoin network. In the event his demands are not met Gavin plans to join Mike Hearn's Bitcoin-XT project which is a fork of the Bitcoin client where Hearn implements patches that Gavin's current affiliated developers find too risky to implement in any mainline Bitcoin client. If Gavin defects to Bitcoin-XT he plans to work with Hearn to lobby merchants, miners, and businesses to move to Bitcoin-XT. Previously Mike Hearn was responsible for the March 2013 Bitcoin network crisis."
Original post: http://qntra.net/2015/05/gavin-threatens-to-quit-bitcoin-development-and-join-hearns-fork/Based on this article it seems like a development choice to work on a second route without the full team behind it.
As it is I see no issue with following different routes
Consensus will be reached through multiple paths but until its needed people will use Core and if it proves to be a significant issue move to XT if this is a two route fork then it could become one of Bitcoins first splits.
We will see though if unity is kept or not.
It is a bad thing that one person currently has so much influence on the bitcoin perception
him leaving should not cause more than a small dip on the news, otherwise it has become to centralized around him.
It is a bit concerning that Bitcoin is centralized in a sense on the reliance of one particular dev but that aside I can understand Gavins role and it does remain important.