For bench work the backlight isn't important. When I find myself troubleshooting some equipment in place, the light is typically bad and the backlight can help. Mostly it annoys me when it times out.
Yeah, I can see how it might be useful if I was working in racks of equipment where the only safe place to sit the meter is in shadow, if the equipment itself is that poorly lit I'd want some extra lighting before I'd touch it.
Fortunately for me I worked in data centres where the lighting was always good and there was always a well lit, safe place to sit the meter.
I have 3 multimeters that have a backlight feature and I have never had the need to use the feature. As Fungus has already mentioned, if you need to use a backlight, then it is certainly dark enough to add in some other lighting in order to adequately see where and what it is that you're prodding.
Not necessarily, it might be possible the only safe place for the meter is in a darker part of the equipment where a backlight would be useful, but that'd be a rare occurrence for me.