There are already enough sports where being small is a huge disadvantage. I played rugby in high school. Alvaro Bautista would have been punished on that pitch, just as I wasn't born to be a successful racer.
Also, heavier riders would have an advantage with a minimum weight because they can use their weight in the corners while the lighter riders are stuck with immovable ballast.
For me, as someone who idolised David Jefferies partly because he was the first successful racer I'd ever seen who wasn't shaped like either a jockey or a beanpole (in other words, looked more like me), every successful racer is tiny to varying degrees. Who decides the minimum weight? 130 lbs? 150? 200? Should John McGuinness have things leveled for him, too?
I understand Redding's frustration, as his size will always be a handicap in short circuit racing, but them's the breaks. I recall the moral outrage when wee Dani Pedrosa arrived in MotoGP, particularly from the Nicky Hayden fan club (that obsessive from Soup is still banging on about it), about how it would mean a grid of jockeys and ruin the sport forever. In the end, Pedro's size was more of a handicap than advantage, with his tiny bones breaking with every crash and later being unable to generate enough heat in the front Michelin under braking.
There's enough rules in the sport, no need to complexify it even more...