But what's the point of stopping the evil empire when meteor will destroy everything and you don't have any plan to do anything about it? Honestly, the squabble with Shinra can wait. We can go back to overthrowing fossil freaks after the impending apocalypse is dealt with!

That's the thing - the party is wasting their energy on stopping someone who is actively trying to avert a real crisis for everyone on earth. It really doesn't matter that they're using huge material, since they're only using it to save everyone. They could have all easily dismantled Shinra after the fact! Thwarting their plans when those plans involve saving the world just because "they're villains" makes no sense and was really frustrating, tbh.

This is all the more glaring in the end because they don't save the world through their actual efforts - from their perspective it was almost an accident because they didn't know going into the crater that beating Sephiroth would release Holy. It was more like "well, I guess we're all doomed, but we can try and beat Sephoroth and maybe then we'all get an idea or two! So much better than actually allowing people with the capacity to do so try to physically destroy meteor!"

And don't get me wrong - I still really like FFVII and think it's a good game. But if it came out today, it would be torn to shreds for the nonsense that happens on disc 2.