I think stating it is useless is a bit OTT. I was Bronze for a year about 4 years ago (from 10 years previous as a lowly Blue) I really, REALLY valued the free seat selection from 7 days out (usually bagging a SH exit seat every time) and the Business Class check-in facility.
Believe me, when you arrive at an outstation to check your bag in and you see the standard queue being some 40-50 plus pax long but only 4-5 pax in the Business Class line you really appreciate the Bronze level
Agreed though, Silver is the really valuable first level tier because of the lounge access. Having been Gold for 2 years now, personally I don't see too much difference between Gold and Silver - it is the difference between Bronze and Silver that is the valuable big step IMHO.