Honest answer: Faith.
(and perhaps greed).
If they can convince enough people to get involved, they might be able to convince someone to add it to an exchange or make and exchange, and might convince someone to give them money for it and might convince people to take it seriously. Works the same for everything else.
So it's all speculation
Are thoses 300 opened feathercoins-threads not good enough for you that you had to create a new one?
Eheheh, sorry about that
Free market principles which tend to escape this generation. If you support the direction of a product, puts your money into play. If you are against it, great, no time wasted and focus the passion on what YOU support. Ultimately, if enough people believe in the coin, a community will develop to support the goal. When I look at supporting any project I need to average how much per hour I'm giving up that I could spending time working on something else. I look at the ROI and go from there.
Personally, I like the people working on different projects supporting Feathercoin. While others spend their energy trying to talk down about this coin and that coin, others are looking to push their passion forward. Critics are 'cute', they keep us all pushing harder.