Actually, KotOR (and TSL) are VERY mediocre games in every way possible except for the storyline (which is pretty darned good, but still not perfect).
Let's leave those rose tinted glasses off. The gameplay mechanics and graphics were pretty awful in KotOR and TSL. Even for their time.
KotOR was one of the best looking Xbox games available at the time... Especially cutscene-wise. There's a reason it won so many awards and is still talked about so highly even 10 years later. As far as gameplay mechanics, that's fully your opinion. Personally, I, and a lot of others loved the d20 style combat. Some hated it. That's irrelevant.
There's no room for "rose tinted glasses" when a single-player game comes around and makes thousands of people play through it numerous times (like I said, 20 in my case). It's obviously doing more than a few things right. If TOR was half as good as KotOR, I would have AT LEAST played through each class story one time by now like I originally intended, which I haven't been able to bring myself to do having played since early closed beta, and there are many others like me.
The simple fact is that TOR just isn't as compelling as KotOR. It's watered down, generic, repetitive, and formulaic... most of which can be attributed to it being an MMO instead of a single-player experience that is unique and one-of-a-kind like a direct sequal (KotOR III... not the JK storyline) could have been.