I would dearly love to know what their thinking is on this.
I would like to know that too. It's probably a kiddie not knowing anything about ecommerce that messed it all up. Money is leaking away from merchants and BitPay itself, so it has to be corrected at some point. If something is working, don't break it. How difficult is it to understand for people.
As BTCpay or whatever it is is laudable but it doesn't have banking and that's what most want.
Indeed, BTCPay at this point isn't viable for most of the simple merchants only caring about that extra bit of revenue. It just requires too many steps to set up; it requires you to take care of hosting, set up an exchange account, verify yourself in order to get your fiat back, be subject to different taxation laws since you are dumping yourself now, etc. Just not accepting Bitcoin would be an easier option for merchants.