Every big social media site there is has the option to issue karma to comments (whether they call it karma, likes or anything else) and none of them force you to be stuck with a misclick forever because of some utterly bizarre idea that you shouldn't be able to change karma issued. This has happened to me twice now, mainly because I use the site on my mobile and have it pretty zoomed out to not be scrolling a lot.
Maybe there is some weird idea that this is a neat little change that differentiates the site in a nice way, but it is not. It is utterly stupid. It's a lack of basic functionality. It's infuriating and makes me think poorly of the site. I seriously hope it's just a matter of not having the competence to implement changing karma (which would be concerning itself) because if this is a conscious design decision, it's one of the dumbest I've ever seen. Even if somebody doesn't make a mistake and just changes their mind, I can't see why on Earth you'd want to stop them from that.
Please do something about this bizarre, ridiculous feature.