Sure, most downmarket cars don't have the ability to switch off the stuff, but then again who wants to zip a Fiesta around like Vettel? (Well, the ST is amazing, but I digress). Funny thing though, most of the high-end vehicles still offer plenty of ways to shut down all the aids. Hell, most of 'em come with a Big Red Switch conspicuously labeled "RACE MODE" that handily switches everything off and resets the suspension for performance. I take it that should all be banned, no?
Come to think of it, why should ANY car capable of exceeding 75mph, or getting there in 15 seconds, be legal? Seriously?
Also, if you enjoy a sports car with anything other than TC and ABS (both of which make it faster) you have no business wasting money and fuel driving it.