But what's the difference whether it's scam or not? You still do not lose anything, you do not invest your money, you do not perform any very important and valuable work for which you have to pay. You are given coins for free, which in the future can have some value. Is not it?
Well, first of all I would not feel good at all being someone who invites people to join scam project, for example, via posts on bitcointalk advertising given coin. I know people should decide on their own, but I would still feel like an idiot posting messages like 'come join the new-best-ever-completely-not-scam-coin!'. I would rather stay poor than deceiving people into believing projects I don't belive, just because I wanted to get some free coins.