I fail to see what he would be scamming people out of..
If he's legit, that's cool. If he's not, who cares? He's not hurting anyone.
The money that he requested to fund his investigation and other activities? Their personal details? Their time and attention? He kinda derailed any community attempt to deal with MyBitcoin and figure out what happened, not that there was anything much that could be done anyway.
If you *donate* money, it is not really a scam. Whether he decides to put the money towards an investigation or buy porn memberships is up to him if you give him your money. Sure, it's not ethical to ask for donations for one thing and then turn around and spend it on something else, but it's not like he's asking for your credit card info.
Personal details? People give out their personal details every day. Ever heard of facebook?
Time and attention? Can't remember the last time I heard someone claiming that someone scammed them for their time and attention, but ok.
Regardless of whether or not he's attempting to investigate the matters of what happened with mybitcoin, it's not stopping you or anyone else from getting an investigation of your own off the ground.