The maximum replies is only for your First Day. It’s part of the spam filter. 
Those restrictions disappear after 24 hours from your first post. 
The forum works on trust levels, so the more you engage with it (logging in, reading, posting, liking, etc) the more it assumes you know what you’re doing, and the more perks you get. Trust Level 1 have 50 likes a day to dish out, but when you get to Level 2 after about two weeks that gets upped to 100 a day (and a 150 at TL3).
The forum uses the likes to generate summaries and highlight popular topics, so if they were unlimited none of that would work any more. You should find it less constrictive when you get to TL2 next week.
You can find out more about the levels (and how to level up) in Trust Levels.