What's interesting is that if you go back and rewatch the whole show (and maybe you have by now), the earlier episodes that seemed so terrible suddenly snap into focus, and you realize the showrunners had a better handle on the whole thing from the beginning than you realized.
Or at least, that was my experience. I also went from trashing the show on forums in S1, to crying over it by S3. When I went back and did a full rewatch, I realized these characters, in their three-dimensional forms and arcs, existed from the very beginning. It's almost like I was somehow watching it incorrectly at first. Just as an example, I know there was a lot of coverage/chatter about the shift in focus to Donna and Cam, but they were fully fleshed-out human beings from the pilot onwards. And they were both portrayed as being technically talented AND multilayered. Yeah, they gave the boys more screentime at first, but the girls were never just the wives/girlfriends.
Same for Bos---on your first run-through, he seems like a stereotypical good-ol-boy middle-manager. On rewatch you realize they were laying the groundwork for his character arc from the beginning.