There is no worng or right here.
There are Spec Miatas that have pro built motors and are built to the full extent of the rules. My ITA car is not built to the full extent of the ITA rules. No overbore, no balancing/blueprinting, no tuned ECU. Just a $500 junkyard engine with OBX ebay header and a short intake with pulleys. My car has a beam axle and has shitty brakes and weighs 2530ish lbs at the end of the race. I also run on Toyo RA1s even though ITA rules allow me to run far better R-compound tires.
I can beat lesser Spec Miatas, but ones that are prepped to the maximum extent of the rules, I cannot beat.
Now, if my ITA car was built like Greg Amy built his and ran it on Hoosiers, then I would agree with you. But I like to race on the cheap and win. After all this is supposed to be amateur and fun.