As a casual player these days, the trend seems even more obvious to me. Change the stamp every ~5 years to encourage bat sales. The serious players stock up on bats (spurring sales), the casual players are forced to replace a bat they otherwise never would (spurring sales) and the bat companies can brag about their "new technology" (spurring sales). Everyone wins, except for the player...
There's been three different "legal" USSSA stamps within the past ~10 years, and yet all the bats still perform nearly identical? C'mon...
Sure, a new 240 might exit 5-10 mph slower than my OG Booger from 2005, but that's not making any meaningful difference. When shortstops are having to armor up like NHL goalies, you know something is still broken. If sanctions actually cared about safety, they'd just switch to wood bats and call it a day. Except that would hurt $300 bat sales, so can't do that...
Let's correct the factual inaccuracies and then we'll discuss your assertions. USSSA has changed the approval stamp twice in the last 30 years, in 2012 and 2020. You want to guess how many times USA has changed their stamp in the same time period? Three times, 2000, 2004 and 2015. The 2012 stamp, everyone was given two years before the hard ban went into place. the 2020, everyone was given 4 years before a tournament only ban went into place and six years before the hard ban goes into place. The bats don't perform anywhere near identical. I played with a couple Conference players before the 2012 stamp went into place and have been umpiring Conference for the last six years. There was a notable difference in both cases where the balls are not flying as far or as fast as they were before.
I've said for a year the biggest issue was that USSSA gave a stop production date rather than a stop sell date. This allowed manufacturers to ramp up production for the last 6 months, then stockpile them at retailers to continue to sell. Didn't help that not many bats were sold or broken in 2020. The expectation was that most of the bats would work their way out of the game naturally.
10 mph exit velocity difference is the difference between a pitcher dying and popping back up and staying in the game. If you let the players today swing that 2005 Booger, you'd be losing a pitcher every weekend due to broken bones.
Shortstops are not suiting up like NHL Goalies, some pitchers are suiting up like an NHL optional practice. The most any other fielder is wearing is a mask and cup. I've never seen shin guards, breezers, chest protector or full helmet.
Don't disagree with you about wood bats being safer. Who's going to be the first to do it? That's what's stopping it from happening right now. How many people are going to play that sanction when the others allowing composite bats. If USSSA does it you'd be here screaming about all the money you paid for a bat you can't use. USA can't do it because they have too many other programs besides adult slow pitch. One Nation won't do it because if they do anything player unfriendly they are going to cease to exist. WSL, ISA and the rest won't do it for the same reason.