what was your stack size compared to the other stacks, especially the other short stacks?
'shortest stack' doesn't mean much. you could be the shortest stack with 10 bbs and you can be the shortest stack with 25 bbs. you would play 77 differently for both stack sizes.
assuming you were short stacked (~10 bbs) and no other opponent was shorter than you, then getting it in with 77 on the bubble is perfectly fine. especially so the wider the gap between you and 2nd shortest stack. if you have 10 bbs and 2nd shortest have 11 bbs, and the table is very loose with lots of pre/post flop action. maybe you could make a fold with 77 and make it in the money. but if you have 10 bbs and 2nd shortest has 30 bbs, well then you need to do something otherwise you're likely going to bubble the mtt and shoving 77 for 10 bbs is the best option option. of course, this depends on preflop action before it gets to you but, for simplicity, lets assume you're open jamming or jamming over a few limpers. of course, if there is a raise, cold call, 3bet before it gets to you on the stone bubble and it's likely stacks are getting in pre/post flop, then yeah, you could fold and take very likely money spot. but, for now, lets assume there is no action other than limping in before it gets to you or you open jam with 77.
sure, you could fold your way down to nothing and hope another player gets busted before you do but that's not the best way to play mtts and it doesn't always work in your favor. when you're short stacked, you don't gain chips and build your stack up by folding. the main goal as a short stack is to play spots that can increase your chances of finishing deeper in an mtt, yes, it sucks to bubble and mtt, but you have think about long term results.
if you fold as a short stack, what are the
odds of you making the money? it's pretty slim, especially if the table is smart and is watching the bubble closely. so, lets say you have a 1/10 chance to cash if you fold all your big spots where you should be jamming. not that great, right? well, now lets say against a call range, you have 50/50
equity and now you double up 5/10 times to 20+ bbs. now you have a bigger stack, a much better chance to cash, and a much better chance to run deep in the mtt. 1/10 chance in cashing and keeping a small stack or 5/10 chance of cashing with double your stack, what's the better option that'll give you better long term results? and this isn't even times you win pots uncontested and you pick up a ton of dead money when you shove as you still have fold equity. so, you're just increasing your chances even more to cash and finish well in the mtt.
so, yes, assuming you're short stacked with ~10 bbs, your shove with 77 is perfectly fine and is a good shove. don't think it isn't because you bubbled and didn't cash. that's fine, that's going to happen. i've jammed aces on a bubble and lost, and it's fine. things happen. variance happens and you can't doing anything about it. however, putting yourself in a much better situation to build up your stack, especially when short, and finish in a much better place in a mtt will always work more in your favor. it is high risk, but also much higher reward.