fnmatch vs regex

Hi there, I'm NaN.
Recently I enrolled to this mailing list thanks to the GSoC.
I've looked the Ideas Page but -unfortunately- some projects are very
difficult for me.
I've looked the source code and I've seen that to perform a search
with a pattern to the branches list (and other commands) git uses
fnmatch() and so supports the glob pattern.
I haven't never massively used the branches or the tags to have the
necessity to filter in a particolar way the results, and the asterisk
has always worked very well.
But: why the decision to support the Blob Pattern instead of the
Regular Expressions?
With your experiences can a patch like this improve this side?

Thanks for the awesome work, NaN