DRS is a perfect example of an arbitrary and artificial device. The criteria for its application in each circuit is at best a combination of hunches and guesses based on the performance of the cars at other previous circuits. Which is why it can be anything between overpowering and uneffective. Some circuits have two zones, others have three, others one. There's no rule, only what they think will be best.
As for its implementation, FIA never had the courage it takes to propose and follow through with any technical change which severely slashes aerdynamic dependency and the subsequent effect of turbulence, so DRS was implemented as a band aid. That's it.
I've always hated it. It does not solve the problem of turbulnece but creates a huge distraction from it.
It does take some guesswork in terms of its implementation, and I've definitely not been completely happy how it's been handled, but I think it's been a pretty clear positive overall.
As for 'solving' turbulence, well, until F1 engineers have figured out a way of altering the physics of the universe, they are *very* limited in what they can do. I've said it so many times - high downforce = cars will struggle to follow. It doesn't matter how that downforce gets generated, the best you're going to do is make minimal improvements until you just start stripping off downforce. The more downforce a car requires to achieve optimum laptimes, the more it'll be affected by turbulence.
'Fixing' the problem will require making F1 much slower, basically.
Arbitrary because they have to choose how far behind you need to be before it can be activated. Arbitrarily, that's 1 second. But many cars seem to struggle to get within that distance anyway (because of the dirty air). So, yes, it's entirely arbitrary.
That's still not arbitrary. There's pretty decent reasoning they chose 1 second and not half a second or two seconds or more. Half a second would obviously be extremely difficult due to the problem it's trying to address in the first place. Two seconds would be incredibly lenient as cars really aren't that close at that point and no overtaking would be happening anyways. Of the problems with DRS, that bit is not one of them in the least.