People talk more about the newer games because they are new. We've had almost 20 years to discuss anything that Bally / Williams did, and for the most part we've discovered it all. The Stern stuff is new.
I have for the better part of those 20 years debated anyone who said one type of machine is better or worse than any other. It's all about taste. A lot of collectors when I started loved the B / W games because they were the most likely to be found on location when they were falling in love with pinball.
In today's market, a lot of people who are buying games are buying because they remember how much fun pinball was, but they want the reliability of a new machine, so they are buying the Stern games. And, Stern has been deliberately targeting this market, something that B / W never did (nor did Gottlieb, Sega, Data East, Alvin G, or Capcom, for that matter), and it turns out that people love that about the newer games. If you want to spend more and get something with extra bells and whistles, you can!