That might be difficult as you can be in multiple guilds. I have characters in several guilds as I sure others do too.
If you tie it to primary guild only, it would be then require policing people changing guilds, “hearting” a build, then changing back.
If anything, a system like this would turn into a popularity contest… making it so that it should never be tied in with any form of bonus whatsoever. Then if it’s just plain and simple “like” system, it seems like it would be a nice-to-have as opposed to a core game system.