This is just the latest evidence that the FO has not yet evolved to big-time level. This wasn't handled well.
That having been said, every team needs ST players with speed. It is one of the prerequisites for good ST play, and one that has been missing from the 49ers for years now. The good teams have good balance on their roster and can carry a guy who is basically a gunner and little else.
The problem for the 49ers is that they have a number of other areas where they would like to keep an extra player or two until they have more time to fully evaluate their talent. The DL is one of those areas. Right now it looks like Dobbs and Williams could be decent rotational guys. Silver might also be in the mix. Similar situations exist with the WRs and secondary. So do you cut one of those guys who have the potential to be more than "just" ST guys in order to keep Mays?
I'm disappointed Mays did not turn out to be more than a 7th round pick but I am also glad his roster spot will now be available to someone who can contribute more in the future. Call that "looking for the silver lining on the cloud" but it is pretty clear Mays wasn't going to be worth much to this team.