They were dropped because they didn't sell, simple as that. Yes, the minifig is king in the LEGO world, and it has been for years. As an adult collector, I hate it, but in looking at what kids want, it makes perfect sense. The midi line was expensive, couldn't be used easily with other sets, and was made for display. Yet it was launched alongside the normal playsets, and for as much as a much larger set. They had pretty much zero chance to succeed.
Luckily, there is a solution. It turns out that those LEGO parts fit together, and you can build whatever you want in the scale you like. Just have to go get some bricks and apply a bit of creativity.
You know, if I see links to Brickshelf, more often than not, the first thing I click is the "Back" button.