Look, as long as you have races, both in the real world and in a video game, where the cars are not identical, there will always be drivers with advantages and disadvantages. In fact, very few races exist in the real world where everyone has an equal chance of wining based on their car selection.
Frankly, even in races where theoretically everyone is driving the exact same equipment, drivers will still have advantages and disadvantages based on how a car is set-up for that particular race.
Like the OP, I like to be in races where no one has any distinct advantage, and thus I get together with other drivers who feel the same way and organize races.
However, in no way would I support the idea that the PP system be removed. It serves a purpose, and frankly no handicap system is ever going to be perfect, not with the massive variety in cars and performance variations based on thousands of possible variations of tuning adjustments for each car.
Just like in the real world of racing, mechanics, engineers, and tuners will always find ways of improving their car's performance while still technically following any and all regulations. The same goes for GT5 and the PP system.
Besides, adjusting the power to lower the PP is just another form of tuning, and many people like the idea of being master tuners, both in the real world and in video games, and who spend countless hours testing out different set-ups, adjustments, modifications, to get their cars performing at their very best while still meeting any formal regulations.
So it really comes down to what you are looking for. Driver only races where everyone is in identical cars with identical set-ups, or Driver/Tuner races where within the regulations, different cars with different set-ups are allowed to compete. You are not forced to do one or the other, but you have to make an effort to find races that you will enjoy, and not simply expect them to be there waiting for you online or in the real world.
Anyone who is reading this thread is already a member of
one of the best sites for online racing groups with access to
multiple online racing leagues including
their own official one, where for the most part members are very supportive, race clean, and stay active.
If you can't find a race online that you like, you aren't taking advantage of all your options.