Personally I wouldn't want that. On my machines, the e-stop stops the spindle turning and the table moving. The most likely cause would be senior moment / finger trouble causing the tool to dive into something unauthorised, or the tool clogging up and breaking, or realising the speeds and feeds are somewhat ambitious. Mistakes have been made!

If you have a crash, there's no need to kill the whole machine. And if the whole thing really goes native, the isolation switch will stop any arguments. Unless you are planning to sell your equipment commercially, it's your call what you do. There's no right or wrong answer although as there are humans involved, I'm sure there are strong opinions in favour of all manner of different solutions.