Bitcoin is stupid, but the point of Unicode is that we have a symbol for everything that has a commonly recognized symbol or representative value, or even uncommonly recognized.
If ⅌ gets a character, or all the symbols of the Byzantine musical notation system, I'm not sure why a typically recognized symbol for a cryptocurrency shouldn't.
The weird bit is that they put together a petition. All you really need to do is submit a proposal and show that it's a notable symbol and not owned by anyone in particular or a brand icon.
Here's the proposal to add "goose" to Unicode. They even added a few joke-y bits, but they made a valid argument that "goose" is a symbol that people recognize. And now... 🪿