Nahh.. I understand where you're coming from, but LFS doesn't really fit the "game" that the "career" idea invokes. Anyone can drive anything.. but in practice, they can't. That's the point.
LFS is about your relationship with the car. EACH car. You learn its quirks, and take it right to the edge of its capabilities and, ultimately, yours too. You're a privateer, and you choose your car. You find the one you like to drive most - because it's easy, or because it's challenging.. up to you - and you pit what you've learned against what we've learned, and we see who learned the most.
The career path option IS the LFS community. It's there that you find out whether you're any good or not.. on the multiplayer circuits, against the rest of us. It may be a short sprint, or it may be an endurance race.. you'll find what suits you best, and then you can work at becoming the king of it. Watch the others drive, and beg setups from the winners. Tweak your car. Find your groove.
LFS is the perfect privateer racing environment. Step into it. See you on the podium!
at the moment there's not enough options for those that would just like to race one type of car 
most leagues are swaping and changing cars all the time or only have short seasons in one car... that's fine for now, as we all are still getting to know the cars 
but I'd love a league that just run FZ5 for example (like carerra cup here in Aus in RL) 
and if more leagues catered for one car it doesn't mean you would be stuck with one car, you could always join several leagues or one league organiser could run several categories or classes within their league 