Let me start by saying that I don’t disagree with you that thinking and stage planning are very important when they matter. What kind of plan are you coming up with to shoot 3 plate racks and a couple poppers while standing in the same box?Plenty of other shooting sports have divisions with round limits at 10 and under. IDPA only recently went to 15 with SSP, and is still 6 (BUG, REVO), 8 (CDP), and 10 (CCP/ESP/CO) for the other divisions. USPSA Production (and Limited 10) is 10, and revolver and Single Stack are 8. SASP has a ten round limit.
I think the ten round limits test reloading and stage planning skills, and otherwise make for a tougher match. I shoot revo from time to time, and reloading every 6 or 8 rounds really makes you think harder, and test yourself more. Just standing there and blasting isn't proving much, and I say that as someone who's pretty good at stand-and-deliver.
ETA: these changes were designed to mitigate against what people like me did: buy a nice 2011, slap a 170mm magazine in it, and have a huge advantage against people shooting normal guns.
You made my point in your first sentence. These other shooting sports have divisions that you can choose if you want to limit to 10 rounds. Not a blanket across the board mandate for all center fire handgun divisions.
Everyone already has a mandatory reload because of the first mag 10 round limit anyway. Hell why not double everyone’s practice and only allow 5 rounds? It is for their own good.