One can argue whether it's good or bad but, in an online (or mail order) context, companies absolutely know in general who their customers are. Which has, as I say, both positives and negatives. Mostly I think it's a positive so long as the seller doesn't abuse it.
Yup. From my perspective, this is a feature, not a bug.
There are “Know your customers” laws that require you to know identity of your customers.
For apps, really? What happens if I bought some software in a box and just put it on my computer? I would be interested in reading about that; it seems strange and impossible to enforce.
I do not think most apps need that, but e.g. financial companies needs to identify all their customers.
Fair enough, but then presumably you need an account with them regardless of where you get the app from.