Interest surely has gone down in this site, no doubt, and it is frustrating. Perhaps, as you said, you are just venting and nothing anyone could say would be helpful, but in case you're really looking for constructive feedback, a couple thoughts come to mind.
Looking at the leagues you are interested in and the leagues you are currently playing, they are all pretty similar - moderately high cap, no AAA, and very few roster-building restrictions. Assuming that the unfilled leagues your teams are sitting in and the ones you created are also fairly similar, the pool of people who want that type of league is getting spread out across a LOT of leagues, making it hard for any of them to fill. Perhaps if you created one league at a time instead of four it might have a better chance of filling?
Secondly, part of what makes this site fun is that there's so many ways to play the game, but in my experience, more people are looking for creative, unique types of leagues rather than fairly simple concepts. Based upon the chatter in the last WIS Championship, a lot of people (me included) enjoy the challenge of restrictive roster-building and the type of league you're describing, in my opinion, doesn't offer a great deal of challenge.
So, I'm not telling you how to enjoy this game, but if you're really looking for input, I think these might be a couple of the reasons you're not seeing the leagues fill as much as you'd like.