It may well be a true reflection of the life cycle of a Stern game - but I will say one thing - Stern are making games that we so easily pick holes in. There's stuff all competition - so Stern can operate how they want to. Very recent history has proven the boutique manufacturers are falling over like flies, or picking technology that is not meant to last.
It is a fact - Sterns are not built like Bally Williams. As Pete mentioned, the B/W are more like "pinball experiences". I always walk away from Monster Bash with a smile on my face. i love the game, but would never own one - because I love the "pinball experience" of playing someone else's !
If I had Gary Stern's attention for 5 minutes I'd ask him to work HARDER on QA, put more time into field testing (thus completing code) and get serious with pricing. The pricing I feel is the biggest issue. It has nothing to do with local currencies - their machines out of the factory are not worth the asking price.
TWD is an absolute cracker of a game. Really impressive.