Titans made sense on paper - as the promos said, both Melrose Place and Beverly Hills 90210 had gone off the air, so launching a new prime time soap opera for the new millennium made sense - after all Beverly Hills 90210 started in 1990 as the other prime time soaps were dying and while both Melrose and BH90210 were limping in the overall rankings, they still consistently did well in the 18-49 demographic, even towards the end.
The main problem can be summed up with Charles Pratt Jr. Why, oh why did Spelling think it was a good idea to sell a prime time soap by him? Models Inc had been a mess a few years earlier and while Pratt might have a few fun ideas here and there, he absolutely can't plan something long-term (which Models Inc showed). The fact that Titans got a "re-tool" five episodes in by killing Perry King (something that wasn't the plan from the get-go) says it all. In a way I wonder how it would've developed if it got a full 22 episode season, or even worse, a 32 episode one a la Melrose Place!