They only get disappointed if they expect badly that they could able to pull a win easily on those raffles, but unfortunately those expectation didn't happen and the other people declared as lucky victor on that roll.

If they just condition their mind for not expecting anything and what they just do is to get some entries then let the luck came if we win then good if not still its good for sure that they would never get disappointed or feel bad for ourselves if we don't win on this. Raffle like this need extreme luck and if we didn't posses such state then its less chance for us to win some reward from this activities. But still good to see someone is winning since somehow it can inspired other people to participate more and maybe same with those winner their time would come then they get lucky with it.