Could not disagree more. First you can't learn jack from a corner station. If you want to know what is hard and what is easy you have to put a steering wheel in your hand.
As far as putting a driver from a low HP car into a high HP car and watching them Shyt themselves.....I call BS. I have driven both varieties of cars and I can assure I have learned more about driving CORRECTLY in my RX7 than I ever did in my Mustang. I have also seen guys like Chris Albin (ITB USRRC Champion) get out of his Vw Golf and get into a GT1 Camaro and kick ass and take names. The ITB car has around 110hp and the GT1 car had over 600hp.
I'm a mustang guy and it was hard to transition to my RX7 but what I learned is that it makes absolutely NO difference what you are racing as long as you have some cars running the same speed to race with. Talk about a challenge - try gaining and protecting track position in a car with no torque and a power band that doesn't start until 5K PM. You find yourself trying some pretty wicked crap on the track to get the job done.
Regarding the high cost of the quest for speed.....racing is expensive and in a spec class 3-5HP is a HUGE deal. It is a difference that you can see on the track and on the results sheet....been there and done that.
Maybe YOU don't learn jack from working a corner, but I do. I've flagged at TWS off and on since the mid-90s. I've damn near seen everything there is to see at a track during that time. When you are up in a deer stand, you can really see how lines, weaving, blocking, etc., affect things. You can also get a feel for which group of drivers have a more difficult time getting 100% out of their car just as you can see that some cars are really easy to drive fast at the limit.
I have NEVER seen someone who learned how to auto-x or HPDE in a slow grip buggy EVER hop into a fast RWD car with no grip not spin, and usually within 2 laps. Very rarely, I have seen one of those drivers be naturally fast in said RWD car after the spin. Most just have bad habits reinforced by years of driving a car that was so forgiving that it covered those bad habits up. It may not take them long to unlearn those habits, but they are, imo, there (especially among auto-xers).
Maybe you learned more about what you think is correct driving in your RX7, but that doesn't mean you learned more car control. When you have grip and no power, and good brakes, it's just too easy to push a car. Yes, the window of error for a "perfect run" may be small, but it's even smaller with a more difficult car as there are more variables that are harder to control. As a result, it is harder to run a "perfect" lap in a car that has power, worse handling, worse grip, and worse braking. Think about it this way: you have a road racing track and a variety of vehicles: 1) is a go-kart that tops out at 10MPH, 2) is a Spec Miata, 3) is CMC2 car, 4) is a crazy insane Viper. Each car has a theoretical perfect lap, right? In the easier to drive cars, it's easier to come close to the theoretical perfect lap (% wise). This is why the top racing series all over the world feature cars that are HARDER to drive at their limits: it separates the professionals from the weekend warriors. There's a reason why Spec Miata races aren't televised on Fox.
Now, track position, that is something different. I will give the Spec Miata crowd points for learning how to take advantage of every inch of track position. Because the cars are so evenly matched, AND because they are so easy to drive, Spec Miata races turn into, usually three parades: 1) those who have gotten every iota of horse power out of their car running together up front, 2) those who are down on power, 3) those who are newbs. In each of the three trains, it's so damn hard for the miatas to pull off a clean pass because the cars are easy to drive at their limits (i.e., a higher % of the field can do it than in more powerful, less grippy car fields. You NEVER see a train like that in CMC, CMC2, AI, AIX, etc., or at least I never did). Whoever captured pole almost always wins unless he has a mechanical failure or he makes a boneheaded mistake OR unless the guy behind him goes super ballsy and pulls off some insane late braking and makes the pass stick.
Yes, I know racing is expensive. But having to dyno 40 different exhaust systems for 3-5 HP is GHEY. Honestly, if I were in charge of ANY spec class, to keep costs down, I would design the class so that it has a max HP rating, as tested by a dyno, of 5-10 HP (or some small percentage) less than what the allowed motor rules will allow. For instance, if spec miata stock engine makes 100 hp (I have no idea what they make), then I would limit the class to 95 HP (and I'd probably consider limiting area under the curve to prevent sneaky shenanigans with cheater cams, etc.). A) This levels the playing field between the haves and the have nots, B) the motors themselves probably last longer, which also helps to keep costs down, and C) it's simple stupid to enforce at tracks that have a dyno (such as TWS just got).