I didn't say I don't need to trust anybody. I have to trust even the full client: I need to validate the checksum, make sure I don't have viruses and keyloggers

I didn't say I don't need to trust anybody. I have to trust even the full client: I need to validate the checksum, make sure I don't have viruses and keyloggers on my machine, I have to trust my backup system and have to trust people who understand crypto better than me. Everyone must trust someone, there is no clear line in the usability-vs-trust balance. I'm perfectly okay to trust a web wallet on blockchain.info small amount of bitcoins because they do a very good job with their iPhone app and SMS notifications. I'm also okay to put some of my money into Electrum and some - in Bitcoin-QT. And keep some on bitcoin-central.net in case I need to sell BTC for fiat quickly. Given all of that, it's not fair to say that "the true" client is this one, while all the others - are considerably different. For people who value their time, it's important to be able to sacrifice some trust for usability and vice versa. If we would always tell them that they must use the full client, we are just imposing our personal tradeoffs and do not respect theirs.