Twitter has so brain-poisoned me that it throws me off a little that we cannot like comments on here. (It is actually a good thing for comments to be a "different kind of post" and not have the same privileges a main post does.)
... maybe a good middleground would be the OP being the only one able to like replies (and only on the replies to their instance). Maybe future instances too, but that seems like a bit of a wrinkle.
Sometimes you just want to give a metaphorical thumbs up from across the room than say anything else, you know?