Well. I get your point and I still agree with you on the objective, but I don’t agree on the way to achieve it.
Blindly copying from protools would probably be not very productive (I would rather go for a detailed explanation of what needs to be grouped linked how when why to develop what we need exactly, in the Nuendo environment.)
Plus I don’t want to see Nuendo turning into Slowtools 
We also cannot say nothing is done in terms of grouping in nuendo, obviously, with v6, so It’s not gonna take 10 years to get better / more complete grouping, I think/hope.
I would bet it’s on the road map actually.
I see what is already present as the first step on a longer road. (Maybe dreaming, though )
Embarrassing in your opinion, I can absolutely understand that. Especially when I personally like grouping in Protools… (To be used in protools)
But I also find grouping paradigm in Nuendo quite interesting.
Especially the quick link which is really great (PT does not have that and will probably never have something like that, and that’s a shame. Need I remember you that for a very long time we had to stop playback to setup groups? It also took ten some time… As we have to stop playback to change the length of a loop or even to activate loop playback, etc…)
Not reinventing the wheel, ok. Copying it, certainly not ! We don’t need the same wheel necessarily. (qlink - which is brilliant IMHO -wouldn’t exist I they had done just a copy/paste)
What is possible though is to understand why protools users find protools grouping great and program the same amount of greatness in the Nuendo way.
By the way I think you said it very well :
In Protools you can know real quick what I linked and what’s not.
Good starting point for Steinberg to implement :
readable / editable groups, with some visual feedback of what’s grouped in addition to what’s already in v6.
On that, this way, I agree, yes, definitely…