Aaron Jorbin wins the post title of the week award. Don't poop on Emoji, he argues, in response to some (shortsighted) backlash from the Twitters.
Fixing WordPress to work in more languages exposes emoji. Since emoji support isn’t great yet, WordPress needs to shim it. Most users won’t understand why there site works in some browsers but not others. Some people find emoji annoying. Others find them fun. But as of WordPress 4.2, we all can at least find them.
Also, I want to make an additional point: resources for contributing to WordPress are not fluid for perfectly even distribution. Meaning, you don't just tell someone to work on something. Passion is a huge motivator for a contributor to open source projects.
Seeing Gary Pendergast retweet negative comments regarding Emoji made me sad. He (and others) have spent their time making WordPress better, in an area that's important to them — not to mention important for WordPress's compatibility with many other languages.
If someone commits to make something (like supporting utf8mb4), it's because they are passionate to see that thing come to fruition. Don't dare tell someone who willingly commits their time to an open source project that they should have spent their time elsewhere. Seriously, think about how much of an asshat you sound like if you take such a position.
Be thankful that there are hundreds of people making our software better every single day. And if you think the focus should be elsewhere, get in the ring and quit complaining.