Mako shit had content - it had tons of mats for crafting, points of interest, bits for other quests, the occasional firefight. It also had a different feel for driving depending on gravity.
Never understood the Mako hate, I loved the damn thing personally, and it was a big part of giving me a sense of actually travelling around the galaxy in a spaceship, something badly lacking in 2 (never tried the last one, 2 was such a downgrade for me).
Could it have had more and better content? Sure, but it had enough to keep me mildly amused.