No.
You're entitled to hold whatever opinion you wish, but
you're only entitled to express that which you can reasonably defend - and there is no reasonable defence to remove cars from a GT game that other people enjoy driving simply because you don't.
The grounds that these occupy space that could be taken by other cars that you might enjoy driving is baseless - every car that can be in a GT game already is and we know this because they are. There is oodles of space left on the disc, so there are no space limitations - these nasty little cars you don't like aren't occupying space that could be better used.
PD are simply limited by what they know about (they're making a car encyclopaedia and introducing niche manufacturers like KTM and LCC to the world... do you think they don't know about some cars that you do?), what they want (ibidem), what they can licence (this is the biggie), what they can get hold of to model and the time they have.
The assumption that other cars can be on the disc instead of the cars you don't like requires you to believe PD either lack knowledge of cars, lack desire for cars, went to the trouble of getting an expensive licence and chose not to bother, went to the trouble of getting an expensive licence without getting hold of a car to model or went to the trouble of getting an expensive licence and ran out of time.
Incidentally, the proportions of cars in Gran Turismo by region are:
GT1 - Japan 89.9%; Europe 3.7%; North America 6.3%; Other 0%
GT2 - Japan 67.4%; Europe 21.4%; North America 11.1%; Other 0%
GT3 - Japan 63.2%; Europe 24.7%; North America 11.6%; Other 0.5%
GT4 - Japan 62.0%; Europe 24.8%; North America 11.4%; Other 1.7%
GT5 - Japan 60.4%; Europe 26.5%; North America 12.0%; Other 1.1%
You can spot the trend yourself.