I know most people dislike backpaddlers like a snowball to the face. Backpaddling is part of the "keyboard-turning" universe which has even become something of a curse-word recently. Whatever you do, make sure no one sees you backpaddle or keyboard turn! You'll never hear the end of it. Some people even unbind the default backpaddle key just to make sure they don't accidentally do it. And today I heard a friend of mine had bound that key to a macro which would whisper her "stop backpaddling, nab" if she pressed it.
And even though I can only see one reason for ever wanting to keyboard- turn, and that is when being busy with your other hand eating something tasty, I actually think backpaddling has received more scorn than it deserves. Backpaddling is ultimately about positioning yourself, and therefore it has its good and bad moments. Let's look at when it's definitely not ok to backpaddle, and the few moments where it might be ok.
Not ok to backpaddle
There is one good example of a situation where you definitely shouldn't backpaddle. That would be any situation where anyone is trying to move out of something hurtful, usually some kind of fire or the like on the ground. Why is this? Because backpaddling is slower than strafing which means you get out of the bad stuff slower if you backpaddle than if you would run forward or sideways. And the longer you stay in bad stuff the worse of course.
The problem is that people act as if backpaddling always is about getting out of fire. Well it isn't.
Ok to backpaddle
In some fights you need to stand in a very particular place, like fights where you have to keep a special range to everyone else on a limited amount of space. Or like on Festergut where you want to keep range but also stay close to get to spores. This means your positioning will need some micro managing during fights, to optimize your own position with regard to everyone else and what is happening in the room at the moment. Being able to backpaddle a yard sounds way more practical than turning around to run forward a yard and then turn around again to face the right direction or strafe around. You could either press one button for half a second or press several buttons for a while to accomplish the same goal. And if you don't want be called a keyboard turned you'd also have to use your mouse to turn, which you don't want to do as a healer, where you need your mouse to target stuff all the time. With backpaddle you can move and heal at the same time.
Maybe some classes benefit more from being able to backpaddle than others. Healers, like mentioned, do not like to have to use their mouse for anything else than healing ever, but I can imagine most dps classes have less issues with this.
So, people backpaddle to get out of fire to position themselves in a better place. But at that moment backpaddling isn't fast enough and shouldn't be used. But when you don't need to position yourself fast, but with accuracy, being able to use backpaddle is way more practical than strafing around. So don't unbind it!