I am not with increasing the block size, that was just a one-time incident and it's very rare for pools of transactions to accumulate like that, normally my even small transactions doesn't need more than one or two blocks to confirm. I think the current system already proved it's efficiency overtime. No need for a very big change currently.
If a mega merchant as Amazon is accepting Bitcoin as payment option, then all blocks will be full nearly instantly. That might be a reason for them NOT to accept Bitcoin payments as 1MB is simply not enough. 2MB is what we need if we want to attract mega merchants.
Exactly... the risk for big companies like amazon would be way too high that they can not use it after developing it.