If people are unhappy with the low car/track count, and voice that displeasure, that has merit. It's their opinion. You're writing it off as invalid simply because it doesn't line up with
your opinion.
You're correct that we haven't seen every last aspect of the campaign. But from everything we've seen so far, it looks like nothing but license tests, passing challenges, or a handful of auto-x style events. So when that's all people have been able to glean from the game's campaign so far, yep, they're going to come to the conclusion that's it. They may be wrong upon release — but they're going by what they've seen so far. It's really no different than you being hyped for the game without knowing what's in it, too: you're just on the other side of the fence.
You made the comparison to GT3 (otherwise known as the best GT game
![Tongue :P :P](/wp-content/themes/gtp16/images/smilies/tongue.svg?v=3)
). That came out less than a year into the PS2's lifecycle. GT Sport will be landing a month shy of four years into the PS4's.