That's fine if you live in the part of the UK which is most populated. Live anywhere remote (like the Scottish Highlands) and the vast majority of couriers charge extra - sometimes ridiculous amounts - to post to the far reaches of the UK. Royal Mail and Parcelforce do not, so for those of us living in such places these services can be the difference between placing an order or not with a supplier (as the suppliers simply pass on these extra courier charges to us as the customer - next time you place an order for something have a look at the delivery section and look for surcharges). I believe the key is choice, not necessarily to refuse to use a particular supplier en-masse.