Apart from anything else this could push someone into flying in conditions they do not really want to - day 28 and they are down to fly but have a bit of a cold, if you only need a couple of circuits to get back in check then most would probably stay on the ground, with a full hours check out then you might push yourself to fly.
Another thing with this is it can actually be bad for business, if you have to do a full hour the temptation is then to leave it until you need to do it (after all, you could do this then go another 28 days), this stretches until the pilot actually needs to renew and the club may have lost a load of rental - at worst he then decides that he is not using his license and just stops flying!