I would agree that having AWD is not a bad thing in general. I think it can be risky when it's oversold to a "layman" for lack of a better term. Especially when most of these commodity SUV's are sold on rock hard eco tires.Many modern awd systems are actually active all the time, just at varying levels. See my post above somewhere w/r to the Haldex systems which are often described as "sends power when it slips". The notion that it has to slip then you get power to the rear is quite old-school at this point. Driving a vehicle where you have power at varying levels to all 4 wheels all the time is v. helpful in a variety of situations including even just wet roads. I don't disagree that awd has become the popular thing now and almost every small SUV/CUV comes with it when for many a basic fwd vehicle would suffice but having this additional capability isn't really a bad thing for most folks and it comes at a slight cost in the end of mpgs and a bit more $$$.
I'm not familiar with the intricacies of each auto makers AWD systems. It's hard for me to believe commodity cars such as a CRV, Rav4, hyundai/kia, nissan products are constantly sending power to all 4 wheels. It completely goes against the idea of efficiency. I also suspect the sophistication of these systems is overestimated. How can you have some space age AWD on a $25k vehicle? But that's just my thought, not a fact.