Why are My Tags NOT found in RB Search?

Why are "My Tag" values not searchable in RB?

If I have a My Tag of "90s", it would be very useful to be able to search a folder for all the 90s tracks. 

I know My Tag is made for the Category Filters, but I have so many of them that it is really difficult to scan through them all. I just want to type in the feature I'm looking for in the search bar and have it all come up. Otherwise, My Tag is no better than adding 90s to the Comments, which I'd prefer not to do, as I want easy to remember standards.