Agree with all the comments about the GTI aiming to be an all-rounder but that was something to boast about like 10 years ago, not any more. VW got it right first yes but today the competition is offering its most dynamic packages with the same intent in mind: 308 GTI, i30N, Civic Type-R, Leon Cupra , 2018 Megane RS (coming in 5door for the first time and you can bet with a compliant suspension, at least in one of its modes), are all just as spacious (if not more in some cases) and comfortable so there goes the "daily car" card the GTI could play up to now...
So, lacking in dynamics, pace, and not being particularly "daily-er" than any of its rivals the only area it can hope to come out on top is the cabin feel and subtlety of its looks which don't sound enough if driving performance is high up on your list. In fact if cabin and premium feel is what you're mostly after you could probably be just as happy (if not more) in a 2.0 TFSI S-line A3...
Just to be clear, I still like the GTI's looks more than probably all of its competitors but I know that to have those I would have to settle with a slightly lesser car in every other department (it was actually why I ruled out the standard GTI and was ready to sign under the dotted line for a Cupra 2 years ago) and that is the frustrating bit. Especially when you know that focusing a bit more on the suspension and engine would not take away any of its daily capabilities and only provide gains to the driving department (i30N, Civic Type R and Cupra are great examples of this).
I also see but don't agree with the need to create all that market space for the R. The R will always have the AWD for those that care about it or need it, and an extra 20-30bhp should be enough for it to retain its flagship Golf status, not 70bhp as was the case with MK7 GTI vs R. That's killing the GTI in comparison to its direct rivals.