When you join you get default subscribed to a lot of subs (including some really retarded ones), but most people aren't actually interested in that stuff, so there's no activity despite have 35k+ users.

A lot of those big subs are only moderated by M7 and aren't really actively maintained.

Assuming that 38k number accounts for most accounts, you're talking about like 40k users that have ever signed up for Saidit. It's still a really tiny website compared to something like reddit, and it's hampered by a large part of the userbase being genuine racists, white supremacists, etc.

We just don't have a large active userbase yet.