I use "likes" depending on my mood and for different reasons, but I agree they can sometimes be problematic (as in. what do they mean). Same goes for any other social media platform really. On Facebook, it was never really clear what someone meant by "liking" content, either. When I like stuff, it´s usually to indicate that;
- I´ve read their post and respect their opinion or the way they have phrased the opinion (I don´t necessarily agree)
- I really agree with the opinion
- I happened to randomly read that post, and liked what they said (sometimes not having read other people´s entries)
- I liked that they took the time to reply to my post.
People will use likes for various reasons. And we can never ever guess what those reasons are. So I´d say don´t worry too much about it :)