It’s multiple things:
Lots of people don’t know that there is a forum. They might want info, and get it from alliance mates or some other way.
Lots of people don’t care that there is a forum. they are just playing a fun little game. It took me a while to find the forum. I’ve been playing strategy games for a long time, so while there are nuances, there are lots of folks who can do fine without it. they just may not have all the advance information, but it’s a fun little game. This replaced Candy Crush for me - I was simply playing that for my GF to give her stuff. Then I started catching up to her huge level head start, then found this. It was better to not blow past her.
Lots of people who aren’t good at English wouldn’t post here. I’ve experienced a game where during parts of the day that I am awake in the US, the guild chat went into other languages. There was someone who spoke only Spanish, a few primary Spanish speakers with very basic English, , and some people from East Asia with also very basic English. At times my “job” was to translate from English to Spanish, but I had to make sure I understood what both groups were saying. My Spanish was very out of practice, but I read far better than I write.