Well....there are *compounds* and then there are *COMPOUNDS*. As with "polish", "glaze", etc. companies use the word to cover a pretty broad range of products. 3M PI-III Rubbing Compound 05933 isn't all that much more aggressive than a lot of "polishes", in fact it's milder than some I've used.
On some hard clears (e.g., Audis...*my* Audis, this is first-hand) it takes something like the 05933 to remove nasty swirlmarks, the kind of swirls that were inflicted by a rotary..sometimes you need it just to remove holograms. The 05933 leaves things almost ready-to-wax and a quick follow up with a milder product gives a nice final finish so I don't care what they call it (though yeah, the term "rubbing compound" in the generic sense is sorta scary, reminds me of the Dupont or TW stuff in the metal cans).
As old-time member NeoPrufrok found out on his hologrammed/swirled black A4, sometimes you simply cannot fix "minor" problems without aggressive products, and I don't see anything wrong with using a rotary for the initial work. I often do it with just a PC/Cyclo, but it takes me a lot longer than it would if I got out a rotary for the first passes.