You wrote: "You should not be forced to used the more verbose form of the variable name."

Just in case there's a misunderstanding here, NOTHING in PBP is mandatory. Some of the recommendations do, in fact, reflect a concensus among some Perl programmers. Others are held up to criticism as 'one author's preferences.'

And here's another 'one person's opinion' about your observation that it "should it be entirely up to the user to ensure that he used the correct sigil."
Frankly, that idea is anathema to me; IMO, it's just another way to write code that you will have trouble deciphering sometime down the road, and that some future maintainer will almost certainly find problematic.