Not that surprising. Diamond started sponsoring the DCC at the Executive West, and it was a shot in the arm for the American pool scene which was seeing less and less major events. The better players/pros knew the Red Label Diamonds played wonky, but there was SO much action in those days with lesser players, that after a year or two, it became very much worth it to have a Diamond to practice on before the event, because there was a LOT of money to be made, both in the myriad of events being held during DCC, and the side action. The best players quickly figured out how to adjust, so that didn't make much different. Diamond made it's deals to be used in other events, and a new table company became firmly established.
Brunswick had been resting on it's laurels WAY too long, and such a simple design change as Diamond making the pockets leather, and flush with the rail, meant that one no longer had to deal with streaks of rubber being left on one's cue shaft. And one could play shots out of/over the pockets with a level cue, leading directly to more accurate play.
It took a few years, and the help of realkingcobra, but the flaw in the Red Labels was identified as an incorrect downangle on the rails, and this was fixed. Pros actually LOVE the way the modern Diamonds play, as they make banks possible that will not go on Gold Crowns. You can use much more finesse in slow rolling certain safeties in both 9 ball and One Pocket.
I came up playing in the Northwest, around Seattle/Tacoma, and the number of weird table setups was pretty significant. Adjusting to different table conditions is part of the game, and it is a skill that can be developed. If people are whining about how Diamonds play, then this is a skill issue. If pros can run 5-6-7 packs on them.. And someone like ME can put down a 4 pack on them... They play just fine. Git gud.
