I agree. I think Google is at least somewhat smart enough to grammatically check content and discount it based on that score. If not, they could increase relevance by doing that.
I'm in the same boat. I tried several years back to create some sites and between getting very little traffic to what I put time into and just getting myself to write I eventually abandoned all my content creation sites because I had to face the fact I didn't have a good content strategy and even if I did I wasn't doing the writing work. Topics I'm interested in didn't really help and even if I were interested most stuff I'm interested in either has an incredible amount of competition or lacks things that could be blog topics.
I wish I had more advice. What I did is focus more on things that weren't dependent on me creating a bunch of content to get traffic. That lets me do what I like to do, but I'm still figuring out the traffic strategy to drive traffic over my competition or at least take some of the market share.