Should probably have rephrased that.
I personally don't believe 3000AD has a checkered history.
Some of or most of the other folks I play other games with believe there to be a checkered history of 3000AD games.
From what I got from them about "Checkered History", it was something about some sort of trying to figure out how to move around between game windows, and other things I don't remember off the top of my head.
As in, they tried it and thought they were too "something". Too hard to get into, too this, too that. Too difficult to figure out how things worked, or too lazy to try to find help themselves.
All I know, is I mentioned Line of Defense, being developed by 3000AD, got a short pause from them, mentioned Supreme Commander's name, and got something like, "That game is probably going to be crap".
I don't doubt that my tastes in games are my own, just that those others who have not enjoyed games that are difficult, without a Manual/ Handholding/ Player's Guide, will be missing out on what I believe Line of Defense is going to offer.