I played in 9 sanctioned events and a handful of non-sanctioned events in 2012. I played MA3 all year, and wormed my way from placing no-cash, to placing last-cash to placing 4th, then 3rd, and finally winning my last event of the year with a seven hole sudden death play off against a guy with a rating 40pts above mine. The other guy cracked a joke when there were some guys wondering through our fairway, "Don't they know we're battling for first place in the second worst division?!?"
And that's one angle on it. From a different perspective, it was the most exciting DG I've ever played, and will be one of my favorite memories for years to come. I feel accomplished because I worked on my game all year to get to that point; to get to where I could play 42 holes and still pump my River out 330' and sink a 25' for-all-the-AM3-marbles putt for bird. Does it matter to the guys playing MA1 or Open? Not one bit.
Does it matter to me? You betcha. Divisional play allows for people who are semi-competent but not great to have these kinds of experiences. It allows people to compete against people they're competitive against. I felt like the playing field was consistent for MA3 in a wide range of events I played over the year. I would not have reg'd with the PDGA or played any of the events except the handful of local, non-sanctioned tournaments if it were not for divisional play.
I'll also mention that MA3 is usually the largest field at our events.