Furthermore the chances of BIP101 forking the network are still somewhat of an unknown since miners tend to be highly risk adverse, what I suspect is happening is that they are giving Core the chance to increase the blocksize before January. If this does not happen before then we might see an exodus of the hashing power towards BIP101. Since the fork can not be activated before January, therefore it does make sense that the miners are holding back in order to see what will happen before then, time will tell. One thing that I am sure of however is that Core will not be able to keep the blocksize at one megabyte forever without causing a split in Bitcoin.

The simple reason why BIP101 will continue to gain support is because it increases the blocksize whereas Core presently does not. There certainly are good arguments that can be made which favor increasing the blocksize and further decentralizing development.