I started to play recently, hit slightly above 200 games now.
Things that lean me towards quitting are:
1)no interactive tutorials for build orders and other aspects. AoE2DE for example have pretty good interactive tutorials, much better then FAF. You get comments and instructions while you are doing tutorial rather then "watch and then try to repeat what you just saw". And absolutely no in-game interactive tutorials for late game.
2) toxic community towards new players. It is really hard to find a game when you have 0 rating, at least in NA. Every time I host a game and grey 0 rating player would join in the rest of players would tell me to kick him. This "rating segregation" problem is annoying.
3)Dual gap and astro. I have a feeling that 99% of the games are Dualgap and Astro. Feels like game should have been called SC: Dual gap. And it is hard to compete with someone who played dual gap 100K times.
4)Luck of random maps. This is somewhat related to previous one. It is hard to compete with someone who knows specific build orders.
5)Luck of player base. At least that is a problem for NA. Have to wait full lobby for 30-60 minutes
6) Nobody plays with new content. Srlsy, we have nomads, why nobody play it?
SC have the best RTS mechanics: strategic map, build queue is awesome, physics of unit interaction but some of the above listed drawbacks are in the way