Only someone who assumes that only a hard limit is actually the only limiting factor.  Again, we've already bumped up against the 250KB soft limit on several occasions; and amazingly, none of the miners have chosen to comment out that line of code.  Obviously there is some kind of cost to the miners for doing so, or a presumption of a cost, that would exceed the benefits to the miner for doing so.  One such cost is simply the work involved in commenting out that line of code and recompiling their mining programs over a relatively few number of tiny transaction fees.  That condition is bound to change, certainly.  This does not mean that miners will start to ignore the soft limit.  It is a community convention that, while not presently enforceble by the running protocol, is still enforceable by the community.  If some miner actually did this prior to the community deciding to raise that soft limit, the offender would prompt some kind of response.  What kind of response, I won't hazard a guess; but those miners certainly don't desire to prompt the community to include rules more strict than what I'm proposing.  It's not in the interest of the miners to invoke a response.