There's dimpling, there's major dimpling, and then there's cratering.
The latter is a new phenomenon, the middle case is becoming more and more common. This is not normal for pinball. Certainly wasn't in the past, and shouldn't be acceptable now.
This was argued about nearly 2 years ago when it started getting really bad with GB. Most people denied it back then, but I think most realise it's now a real thing.
Explanation back then is the same now. It's young wood that hasn't been aged (dried) nearly long enough. Hence also some of the terrible 'ribbing' that's been seen lately.
If you accept this - like other cost cutting - ultimately you will be sorry, because the cost cutting will get worse and so will the end product. Imagine if there hadn't been some push back against the appalling playfield and cabinet quality that Sterns have sometimes displayed recently.
If you're a fan of Stern who for some reason wants them to 'win' and others to fail, or at least not gain market share, you're also shooting yourself in the foot. The fact is, there is competition now. If Stern (or CGC - who have also been suspect re: pfs) are given a pass, eventually it will get bad enough that people won't want to touch them, and even if they improve things, they won't be able to shake the reputation. IMO they came perilously close to this already.
You think we'd have seen a better featured, more complete Iron Maiden (certainly the best Spike era package) if people hadn't been so vocal and dissatisfied, and there wasn't competition? No chance. We'd have seen a pile of crap. Would they have hired all the new talent, at no doubt considerable cost? No chance.