No, I agree with you. The early 70s (the first 3 or 4 proof sets) you can make a case for - no pun intended. However, it would have been preferable if subsequent sets had been much more sporadic. Individual changing designs or new denominations - the 20p, £1, £2, 50p, etc - would have been introduced as single issues in various forms such as regular metal, silver, and piedfort for new denominations.
The whole "several proofs each year" thing has just devalued the proof experience IMO.