the usual blah blah blah I'm used to hear for ages.
we want to donate! then you opensource, and nobody donates.
percentage based stratum miner, even if closed source, is easily fooled with routing or network filtering and in some cases you could even make it mine on your pool instead of dev's (it might work for solo mode, though).
it's not the devs who are gready, it's the miners.
remember that devs are making programs that let miners MAKE MONEY: a previously unheard of "money making machine".
it's not like an android wallpaper.