Yep.
As much as TOS was some of the smartest writing of its day, it was still largely a western in tone, set in space: Ride into town, whoo the lady of the episode, shut up the bad guy, ride out. Now not every episode was that basic. But the philosophy between TOS and TNG are miles apart.
I go back to TOS, but I liked TNG fine. However, yes, they are miles apart in many ways, and I think they should be thought of and appreciated that way. TOS was smartly written, but it also had its campy and swashbuckling sides that TNG didn't have. More often than not, action drove the story and Kirk was almost always the center of the action.
The typical TNG format seemed more like detective show or mystery movie centered around an ensemble cast with different roles to fill in solving the story. It opened with an initial mystery or conflict, then moved on to showing its effects, there would be analysis, a crisis, then finally a revelation and a resolution.
They're so different, it frankly strikes me that there's really no logical reason to expect someone to like both.
TOS was very much pulp-magazine style sci-fi: Light, quick, fun sci-fi, that you could carry in your back pocket. Sure you had a recurring cast of characters, but overall the series was very much more like an anthology style of story telling.
Now this, I would have to agree with. I would have to argue that TNG set a different tone from TOS, one that was to be the standard of all subsequent Star Trek shows, including Enterprise.
For me, I found the new movies to be quite evocative of TOS, especially after watching TOS on blu-ray recently.