I really am struggling to understand why you are interpreting this as anti-rotary?
A Cessna 152 will be charged £10.80
A Robinson R22 will be charged £9.30
You are charged £26.25, but a heavy SEP would also be charged the same.
So you can land an R22 at Coventry for less than the 152. Where is the discrimination?
Coventry have chosen to base their landing fees upon MTOW. They didn't do this to deliberately penalise helicopters - it's an absurd way of interpreting the situation!