My understanding of Gavin's motive is that the hard fork is purely ego driven. There's no urgency to change block size. He just wants to be dramatic and make his personal mark on it. But controversy, technical-wise, is that some Bitcoin users may have their coins lose compatibility with the new implementation. In a sense, it may be Gavin and Hearn's attempt to hijack the Bitcoin name and implement their own coin or make changes to the protocol.
Everything you said is inaccurate. The reason there is a debate is because there are a lot of people on both sides of the blocksize increase, Gavin is not even close to being alone on wanting to increase the limit. He does not want to be the one to make the call on what happens. If you haven't watched a recent Q&A with Gavin and Mike you should, they specifically discuss the blocksize issue at the 27 minute mark
https://youtu.be/RIafZXRDH7w?t=27m50sAlso no one is going to lose any coins unless you are a miner receive block rewards and you start mining on the "wrong/old" fork.