They indeed would not have had it, it would've been all stolen by now.

But I guess what you are trying to say, is that with current valuations, Mt Gox would've upped their game and would've moved to much more secure architecture and infra.

If so: I doubt it. At the time of the heist, they were still running largely from a PHP monstrosity, that was originally built to trade cards amongst hobbyists. The only thing one could say for the Mt Gox people (Mark Karpelès etc) is that at that time, things moved extremely fast. Tech and infra may be good to trade tens of thousands of $/year one day. But if weeks later you are now trading millions $/year, there's no catching up. In hindsight they should've realized their organization and tech wasn't up to it and should've closed down. Because keeping up was clearly impossible.

*disclaimer: I lost significant amounts at the heist, eventhough I never held more than strictly needed on an exchange.