Why hasn't there been any trade paper backs of the late 90s titans series, after the technis imperative? I want to read it, but I don't want to buy all the issues individually. It's not even available on DC's digital comics site, is DC ashamed of it in some way?

It's actually very sad. About 95 percent of the comics from DC put out in the 90s haven't ever been put into collections including the entire Green Arrow ongoing series, Aquaman. lots of Nightwing, Robin, and Catwoman. A lot of Flash too. I'll be wasting my time naming them. Most of the stuff from the 90s have just been forgotten about even before the relaunch which is really disappointing.