The first guy seemed to have a technical problem with a MtGox code. Hard to tell what happened there, even harder to act without evidence. Give him 500 just like that? It'll have to be addressed to MtGox I think.
The second guy is complaining about 1 Bitcoin. There could be many reasons why that single bitcoin wasn't credited. More likely those reasons have more to do with him than with Bitcoinica. Perhaps...
...he used the old deposit address that was hacked as the third guy seems to have done. He is complaining he didn't know about it. Tough luck, if a company I work with is hacked, I'd read about everything that has to with that first before >continuing to use this company< as if nothing had happened.
Then, there is another guy that complains that he forgot his password to his 1000$ Bitcoinica account. I mean, seriously, if Zhou has to deal with such crap on a day to day basis, a wonder his service can still run so smoothly. He must answering people's emails and telling them they are total idiots 24/7.
Disagree. Bitcoinica is a for profit operation. Therefore full responsibility applies.
From my point of view it is fully justified that a customer losing assets due to misconfigured or insecure offerings of a commercial operator demands refund. (The lost password is an exception.)
Calling customers idiots because they lost assets this way does not seem appropriate to me at all.