I don't think they were terribly bad. If they had skipped the constant changing camera angles, stacking of boxes in endlessly repetitive puzzles, the timed sequences and keyboard controls they would have been decent games, I think.
It always surprises me when the developers go for keyboard controls only. Input from players and beta testers should be important to all game developers, right? I still haven't seen any request even similar to this from a player: "I don't want to use the mouse! I don't even want to have it as an option! Please limit the controls to keyboard only. Or possibly gamepad, since all PC players has one."
(I think that the 4th game had mouse control, tough. Other than that, all of the above applies to that game as well).
Having said that, I rather enjoyed the now largely forgotten In Cold Blood, Charles Cecil's game between the good and bad Broken Sword games. It also had keyboard controls, which worked exceptionally well (compared to other keyboard controlled adventure games, that is).