The argument you're expressing, as I see it, is that there is really no difference whether or not the files are stored in /var or /srv because in the end they're bits on a disk so where in the file system they end up doesn't matter. /var was chosen years ago by Unix admins so why change it to /srv?
My argument is that those same Unix admins no doubt placed it there because it made functional sense at the time. Over the years that location became a convention and therefore became an arbitrary location. The LSB is reviewing that same functional choice in light of what changes have occurred in how we use servers and they feel that it makes more functional sense to break those files out into their own tree.
As far as breaking tradition from Unix, last time I checked porting an app of reasonable size over from Linux to Unix is not a simple process. The choice to put client facing files in one directory or another is a minor part, at best, of that process.
I agree with you on standardizing libraries but I fail to see how that has any relevance to where an admin should place their client facing files.