The shell is only one part of the picture - but if manufacturers save money through less material on the outer shell, they'd better make sure the overall integrity of a ball is kept up. The thinnes covers I have seen so far are only 0.5" thin, while older balls are 0.75" or even thicker, even massive without a filler. Modern covers are also more porous than older stuff, so you really have less material on the outside.
One can argue that performance is not affected, but IMHO durability has declined a lot - probably intentionally. I know players who blindly buy the new high end stuff every year, and for them this marketing strategy works fine.
Personally, I like to keep balls which "work" for me and find a place in my arsenal, and I have (after cracking...) become rather cautious. For me a thin shell is a BIG argument not to buy a ball.
Besides, add holes, or some poorly mixed material zones, and the potential for a crack is IMO much bigger than with a thicker-shelled piece. When balls come to Europe via container, they even crack on the way - without holes being punched up.