There have been other threads that resolved this long ago.
Could you please quote other core devs saying they OK this ?
Here is mine :
sipa → i'm generally in favor of a larger blocksize, but only under the condition that there is a proposal that has extremely wide consensus
wumpus → I'm still not convinced we require a larger blocksize yet
Luke-Jr → wumpus: we definitely don't yet - but it's probably something to be thinking about
gavinandresen → wumpus: how full do blocks need to be before you think we need a hardfork?
wumpus → gavinandresen: all of them full, and a backlog of serious (not spammy) transactions
gmaxwell → gavinandresen: First stop pretending that there actually is consensus or that this is easy and safe. We couldn't even manage to get BIP34 right without two somewhat ugly unexpected effects (we burned the most significant bit of the block version number; and the switchover criteria we implemented wasn't actually the criteria described in the BIP)
Source.