It has other features that might benefit itself differently than bitcoin. This is arguable, however, Grin's monetary policy can be viewed as a trial on longterm sustainable mining.
Grin was fun to mine about a year ago, and I liked it for it's privacy features. Now that it's known to be a less private than originally thought it just feels like another altcoin, but one that's kind of a pain in the ass to use. The MimbleWimble protocol still has scalability and efficiency features that are worth building on.
Are there any forks of the Grin yet? If it has some usable features there will probably someone want to improve it.