I agree that GT7 has more than just races, but variety works in the races too. There's a wider variety of event types in FM7 than GT7 which consists mainly of 700pp at this track, 600pp at that track, 800pp at the other track. It's bland as hell.
Neither are close to the series bests, which you prefer is pretty subjective, so I won't agrue with what makes GT7 a better career than FM7 for you, but it's different for me. The licenses and missions etc. are one time fluff for me. They're nice to have, but I would tire of a game made up entirely of them pretty quickly.
As it happens, I tired of GT7 pretty quickly, because the races are so unispired and dull. At least in FM7 the races are proper grid starts and there are far more categories of races. I do agree with your criticisms of it though, and by me preferring it to GT7 I'm in no way praising it as great. It's not.