A thing I've noticed is that some BL fans will sub and soon unsub if they think the story won't give them gay kisses or even sex soon enough. I don't know if your comic is BL, but it has two pretty men in the thumbnail which often attracts that kind of audience.
If you intend to write a story that's not easily digestable romance or erotica, you haven't really lost anything. The numbers may imply you lost something, but if these people had stuck around they would have become pushy commenters instead nagging you for sex scenes.
Another thing I've noticed is that you had a character who used the word "republican" in a negative manner. This isn't a bad thing, but as creators whenever we express our opinions or let characters express their opinions, it has the risk of offending someone. It's just a risk we'll have to deal with. Pandering and trying too hard to make it agreeable to everyone will result in something that's bland and boring instead.
Your art is great tho, the people who unsubbed are missing out.