Because bitcoins work well if what you want to do is something like bank transactions. But waiting 10 minutes is just too much if you want it to work as if it was cash.
SNIP
Please read before replying.
There really is no need for confirmations on low value transactions assuming the merchant (either directly or via a service) has a large number of connections to the network. Double spends are very difficult, even more difficult in the physical world (where risk of caught, losing coins, and timing all become more critical).
Any revocable transaction doesn't require any confirmations.
Any low value physical transaction doesn't require any confirmations.
Any mail order transaction (or other longer timeframe transaction) takes longer than a confirmation anyways.
I know these claims are Heresy to the "church of the 6 confirmations and protection from double spends" but not everything needs a confirmation. Not everything is affected by the "delay" in confirmations.
Some things need confirmations. High value irreversible anonymous transactions that must be completed rapidly. Honestly those are a tiny minority of economic activity but a solution already exists called green-addresses.
Building giant expensive banks with intra bank networks defeats the entire purpose of Bitcoin is a solution in search of a problem.
Simple solution ... just use a bank. Why even use Bitcoin?