[Si Coe]

The issue is not with drivers using multiple sets of tyres - ultimately it is with the need to do so to be competitive.
Fresh rubber is always an advantage, but if the difference is not significant there is little point wasting money on it unless you really want to. Cheque book racers will always try to buy themselves an edge, but frequently its purely psychological.
However modern 2wd cars are heavily dependent on the rear tyres themselves for traction due to all that weight moved forwards. Performance drops off rapidly as the tyre wears, making a fresh set very handy.

Maybe its time to retire (no pun intended) the venerable yellow minispike and replace it with something more durable but less grippy. Something where the 'edge' took a few more races to really wear off, and that encouraged the use of cars where some weight over the back axle was required to get any traction at all.
The money men would still use a fresh set every run, but instead of grumbling the rest of us would just laugh at them spending far more than they need to.....