One of the guys wrote something and published it as open source. The other got to use it for free but still complains with an inappropriate tone. Hard not to side with the first one by default.
In this specific instance, calling the library "incomplete" is a less-than-completely-accurate characterization. What the issue creator wants is easily possible using the library, but cannot be included as default behavior because of licensing issues. This is hinted at, but perhaps not made as explicit as it could be, in the README.
It is perfectly complete and exactly what it claims to be. It's just not what whatsisname expected it to be. Are we expecting OSS developers to be mind readers now?
So the alternative in your view is to not offer anything at all unless it's complete by some objective standard? Does that really sound preferable to you?
An alternative is to offer it, but mark it clearly as "incomplete" or "alpha" (which is what one of the original complaints was about). Versioning it would be even better (say, call this "emoji 0.1").
If someone whines about a perceived shortcoming in stuff which has been released incomplete, but free and modifiable, then they can expect short shrift.
