As I think I mentioned before, developing vaccines costs an astronomical amount of money.
No one will invest that for something like the common cold. Similarly, vaccine development for SARS and MERS got shut down pretty quick because those outbreaks ended up being so limited, both geographically and temporally.
So there's your answer as to why there are currently no vaccines for other coronaviruses - it's got nothing to do with whether it's possible or not.
It's not going to "mutate" into something capable of latent infection either anytime soon (or ever). Those that do belong to completely different kinds of virus families, with dedicated mechanisms for this.