I Think You Know The Answer To Your Own Question
Can you convince yourself that you will not be, in some vital sense, lying to the university when you "accept" the offer, knowing that you might bail on them in a very short time? I don't think you can. I think you were hoping someone here could convince you; to give you permission, so to speak.
(That looks... a little more harsh on the page than I intend it to be. I do sympathize with your situation. I've been in situations where, in retrospect, I was looking for permission from others to do something, too. It happens.)
If anything, I would say this is probably more... expected, if not acceptable... in industry, because both management and labor (even highly qualified expert labor) are more mercenary. The practice of layoffs, RIFs, and bottom lines has produced a culture of opportunism.
I don't like it, I don't condone it. I merely present my opinion of reality.
Ask For Extra Time/A Faster Offer
Others have suggested asking for a faster industry offer. You should definitely do this. It might work. But note carefully: It might not.
Almost no one-- certainly not you or anyone here, possibly not even the hiring manager, maybe not even HR-- can really predict if a company can speed up their process, much less whether they will.
I've been part of one situation in industry, where an excellent, highly qualified and motivated applicant wanted to work for us specifically, and the hiring manager agreed. But the applicant already had an exploding offer in hand from another company. He was very transparent about it.
I was in the room, an hour after the interviews ended, when the hiring manager picked up the phone and told HR in no uncertain terms that he needed them to tender an offer in under five business days. Why they ignored him, I do not know. Maybe they had a good reason. But when I was hired only a few years before, I had an offer 23 hours (!) after the interview ended.
It is just not predictable.
The other side of this is to beg the university for an extra two weeks. But, they have their own internal deadlines. And they are going to know exactly why you want the delay. So I wouldn't count on it.
The Fine Print
You should read it.
The Fine Print, I mean.
Some acceptances are contractual.
Other Considerations
Other answers have mentioned this, but think through carefully what the effects of this might be. They may extend beyond your hypothetical non-colleagues. Are you being hired into a position that involves teaching courses of undergrads? Is the university going to be left so much in the lurch that the undergrads will lose access to qualified instruction?
I've seen that happen, too, so it springs easily to my mind and is meant only as an example.
But the larger point of figuring out who you're really harming with a play like this remains.