Its simple..
1) You can't tell if it'll be playable until you do it, right? (except for stuff which is obviously going to be unplayable, like a PSX emu on GP32
2) People do what turns their crank; its none of your business what they do, so this is a rediculous thread and almost insulting
3) At the same time, many coders are looking for projects, so keeping a list of things to port, or unfinished open source projects, etc, is a good idea. Again.. its up to the coder.. some like to just work on other peoples things, while others just want to create.. depends on the individuals motivation.
Most coders aren't serving a community, thogh that is a nice side effect; they code for themselves, for love of the game, for pursuit of excellence and creation of something nifty... and its a great pleasure that other people enjoy it.
Think of it like music..
Many bands do it for the money; there sno money here
Others do it for the adoration, or for the sake of helping others. This happens.
Still others do it for art.. they make their music, and if it sells or is enjoyed, thats njice, but not important.. many artists do it for themselves.
So its not up to you, and its rude to suggest "you guys shoudn't bother unless it'll be good for me to play". You can suggest "hey, this is unfinished, any devs want to pick it up?" and keep a list, lik eI mention above.. but actually making a general statement just makes you LOOK LIKE A JACKASS to those of us who kill ourselves to make neat toys for everyone
jeff