Mt.Gox doesn't owe anyone the ability to sell BTC for fiat cash. If someone bought BTC then that's their decision to invest in that asset.
Well that is the business they purport to be in. They should be transparent about the actual withdrawals delays and provide estimates based on the current queue.
A person who had traded with them before these problems and then sold BTC on Mt. Gox before these problems developed and are clearly stated on their website has a valid complaint against them. Based on all past experience one would expect that they would continue to withdraw in a reasonable timeframe, say, 2-3 business days. 8 weeks isn't even close to a "reasonable" timeframe.