If the ATCOs cannot enforce a PTL the system fails. They can enforce a feeder fix time so why not a PTL?
Some flow controllers do sometimes, but it can make the situation worse. I recently had a turboprop given a 20 min hold, because they were about 40 mins early. Then;
a/c - we only have 15 mins holding fuel
atc - roger, is JT suitable?
a/c - negative
atc - advise alternate
a/c - we are not carrying an alternate
atc - we can only bring you in early if you declare fuel emergency
a/c - we are not declaring fuel emergency
atc - ????
I do agree though that the PTL should be abandoned. Even with the best intentions, there seem to be valid operational reasons for airlines ignoring them. Also, there is no way anybody roughly on time should get 40+ mins of holding (which is far from unusual), but we don't seem to have the will or resources to go back over each sequence to establish what went wrong. Its no consolation to crews, but I can assure you its not much fun working your behind off all shift and knowing the service provided is rubbish.
My advice, don't complain on here, don't complain on frequency, don't even bother phoning in afterwards. Get you companies to complain, and the higher the better.