Is there a reason why, along with the "add to favorites" "report a problem" and "link to this review" buttons, there cannot be a "review this provider" button, that would bring one to a review form with most, if not all of the variables for said provider already selected?

If one wanted/needed to change one of the variables, they could.  

I think this would not only cut down on duplicates, but also speed the review writing portion along.

the provider's attributes over and over again is that it cuts down on casual reviewers, and thereby improves the overall quality of reviews.

I think that is a bit dubious, but it's there sand box, so we either play by their rules, or not at all.

The op is just making a suggestion to TER to change the system. It is up to TER to change it or not. (I suspect not, since they never did before), but this is what this board is for.

And Fisher was just passing on information on why the system is currently what it is.  I found it interesting, as likely did others.

Which is ALSO what the boards are for.

I guess that makes sense.

Sounds like a bit of "damned if you do, damned if you don't" too though.
Maybe these casual reviewers are only casual because of all the hoops they have to jump through to get a review up.