For the long run I agree. but for the case of 5.4.0 exploit, AFAIK the devs already have another exploit that is more private, hence it makes more sense to keep it so in order to achieve that ideal situation.
But not for the one which the bug used is public already.
Some think that just because the exploit isn't released even if the bug is public, nintendo is unlikely to patch it. I agree it is a possibility, but in that sense it doesn't mean it'll keep future firmwares exploitable in the long run (for that ideal situation), it only means we are in a waiting game ^^.
Not releasing the exploit because it is too unstable (which is actually what the main devs said) makes more sense, because it is true it creates more frustration when something is released and doesn't work properly. However in my humble opinion releasing it could bring other people to improve it and make it more stable, which is what happened already with the previous public kernel exploit. Don't forget there are other people out there who can contribute to homebrew in Wii U but are stuck on 5.4.0/5.5.0, so it's not only giving the chance to more people to hack their Wii U faster, but it also gives room for more homebrew and testing for the community (which would make that situation more Ideal in the long run).
I'm not complaining to the devs, in fact I've been following this thread regularly for over a year, almost daily during this year. And I appreciate all the amazing work done by people like Marionumber1 for the community (unlike other hackers who just love to show off their stuff online), and I respect his decisions. I'm just discussing since this is a Wii U homebrew discussion thread ^^. With reasonable polite discussion we all learn from each other here.