Innovation isn't just in new features. It can be in making older features better. It can be in the rules and programming side of game development.
Not everything needs to be an interactive bash toy.
Less can be more sometimes.
Xenon had a really cool looking tube ramp for its day, and Centaur came out later with just some rollovers, some drop targets and a captive ball, but put me with the two side by side in a room and I'm probably going to play Centaur because it's a better game.

MM really shines to me not because of the theme or the castle toy but because it's a well-designed game from a rules standpoint and there's a reason its influence has shown up in games since from any designer and with a track record you can think of. It's like when flippers were invented and, after some moving around, the pinball makers came to a consensus that two flippers facing inward at the bottom of the box should be a standard.
I can understand if there's a game you would rather play, or own, than MM.
But I can see why it sits where it does in the rankings.
I can understand why it commands what it does on the secondhand market, especially with its low production run in comparison with its popularity.
Had it come out a little earlier during the height of Mortal Kombat and NBA Jam in the arcade, it might have outsold TAF.
All I know is now, we have five pinball makers in existence with multiple games brought to market. 20 years ago, there was one.
Can't say moves aren't getting made in pinball still.