You can dump gears just as easily with one push of your thumb with 1x too, but I can’t really think why you’d want to dump so many gears in one go. You’re supposed to look up the trail and anticipate gears ahead of time so you should never/rarely find yourself in the wrong gear – nothing worse than hitting a hill in too high a gear then having to grind up the cassette, or swap chainrings under power, it’s not very mechanically sympathetic no matter what drivetrain configuration you’re running.
The question is that now with 1×11 and 1×12 you can get the range why on earth would you WANT a front mech and front chainrings?
I went 1×10 because the simplification appealed to me and it got rid of problems the front rings and mech were giving – mainly clogging with mud and ceasing to work anyway. It took a bit of getting used to and I did have to make compromises on the ratios as I am still running an 11-36 cassette so was blowing out of my backside for a few initial rides until my fitness improved, but i’ve not looked back since. Also since going 1×10 I haven’t snapped a chain and my chain usage has dropped from about 3 a year to 1 a year, so all in all its less stress and wear and tear on the drivetrain.
Going 1×10 with an 11-36 cassette took a bit of work and some compromises and therefore a leap of faith that you would get used to it and ultimately prefer it, as I did. But with the latest 1×11 and 1×12 offerings and the gear range they offer its no longer such a big transition.
Different things appeal to different people and dealing with a problem, like I was, usually prompts you to look to something different. If you’re happy running 2x or 3x then great and two fingers up to those who criticise. Until you get a new bike with no front mech attachment of course.