Work-arounds are possible, I don't deny that. But users should not have to take up special provisions to prevent destructive or obnoxious behaviour from other users. It's for the same reason that embedding 3MB images into a thread is disallowed (manually), vertical sig limits are enforced, NSFW must be tagged as such and linked rather than embedded, etc.
Just because you can be detrimental to forum perusing doesn't mean you should be, whether or not tertiary safeguards can be applied.
Take a look at the Help and Support board - count how many of the problems there are PEBKAC. The vast majority of people likely don't have safeguards and don't know how to apply safeguards.
Also I don't have a problem with the song itself, if it was just a yt link I wouldn't have removed it.