When Finale was introduced two decades ago, it used Petrucci as its music font, and recently this piece of work was elevated to emeritus status: it's now considered a legacy font.
Stands to reason, the original Finale designers wanted to watermark any and all of their product's output. Hence:
By now everybody recognizes the familiar treble clef. It tagged anybody's work as Finale immediately.
Before continuing, let's check out a small gallery of other font setups:
Now until Maestro, Engraver, and Jazz were supplied with Finale, you tried rolling your own music font or used Adobe's Sonata, if you knew Petrucci wasn't a publisher's cup of tea. Petrucci was Coda's way of saying that the software was more important than the work you accomplished with it.
I suppose that nowadays Sibelius is a way of telling MakeMusic that Finale is only a conduit for creation/realization, and must not call attention to itself in the final output. It can only call attention to itself within the user experience while doing the work.
Put another way, when you are reading and playing a Beethoven sonata, the publisher and engraver and technology must be invisible, and only Beethoven must be visible. How is this accomplished?
Later . . .
Oh, you were wondering about Petrucci, weren't you? The man, that is.
next . . .