I can definitely see the advantage particularly for health reasons, or if you want to take a few luxuries. Just had a quick look on the Sherpa site and they seem to charge about £8 - £9 per bag per day, so for an 11 day C2C around £90-£100, which is not too bad in my opinion.
For me, my kit, over and above what is in the day bag anyway, is only a lightweight pair of trousers, spare walking t shirt and boxers, light shoes, my kindle, toothbrush and razor. The weight is pretty much negligible so I am happy to carry it. I also quite like being self-sufficient - but only to an extent - no camping gear in my bag! So there, you lily-livered pansies
As far as "fun/pleasure/self-flagellation" goes, I was taught by the Christian Brothers so this is an important part of my suffering.