It's funny because I just realize that I'm using my shift key for multi-selecting in MoI (for nothing) ... well at least when I'm just switching from an other 3d soft.
So strangely, I think I will appreciate that new option too ... even if it will break the ability to work with a single hand (very handy when eating something at the same time :))

I'm not really sure if it's the reason of user mistake. I often get this 'wtf' moment when I see something has been moved or deleted in a model, what even the software I use.
Grouping and locking mechanism is probably our best friend.