I can think of countless reasons one might want to secure their handgun following a situation where it was necessary to draw one in the first place. Administering first aid is difficult with a .45 in your hand, and it's generally frowned upon to just throw your gat in the nearest schoolyard while you perform chest compressions. Police generally get a bit jumpy when they show up on a reported shooting scene & see some guy waving a gun around. If you're in a less-than-friendly locale, so do the locals. All these reasons and many more are why you'll likely never, ever hear a competent trainer teach people to disrobe in order to secure their firearm.
Then there's the matter of just how 'safe' it is to be fumbling around with a heavy loaded firearm in a holster as you try to attach it to your belt. Fairly certain more than one bathroom-stall shooting can be attributed to this ill-thought-out action plan.
Another crack at
@Harriw , who as a self-described 'noob' appears to be have a better grasp of safety & training than many self-proclaimed gun guys. I'd go shooting w/ him any day of the week. Can't say the same about some of the 'experts' here.