Yeah marketing side, but how about the operational cost though? I mean project started from scratch with 0 funds, they're going to 'share' funds here, which I don't think that ICO project will agree upon (at least the way I see it). They needed all the money to cover there expenses and partaking some funds would be their last resort, IMHO. Although I like your idea, perhaps it needed some expounding specially the 'X amount to be refunded', in cases of liquidation.
Ideally, I think, will be more effective to take an % from any token purchase made by the user during their ICO.
The main issue I see with this is that most ICO projects don't have much capital, hence why they rely on an ICO to raise it. If they were to process refunds, how would they have anything left to pay into this fund?
I think you get the whole idea a bit wrong, there won't be any upfront payment to join in this fund, same as ICOs won't do refunds by their own. During ICO, the project should be agreed to share an fixed % and if later this project will turn into a scam or something else will happen to this project, people who participated in their ICO can expect to get a full refund from this Fund.