> public domain

I hope none of your contributors live in the US. If some do I recommend you either do a wee bit more research about the legal situation of public domain code, or they stop contributing.

Why do you think MIT/X11 licences and the like exist?

As an aside, I make regular use at work of echo's -n and -e options (albeit you don't need -n with -e). But if you like life on the spartan side, go for it; UNIX is a pile of crap as is.