I also think we don't need to polarize things to a point of there being a pro ngöndro group vs a anti ngöndro group!
I think some teachers emphasize the traditional tantric approach to Dzogchen while others don't. I never seen a teacher denigrating any form of Vajrayana practice.
In the DC, people also practice tantra according to their own needs. Perhaps the right way to say is that we don't have a one-fits-all formula, a template if you wish, that everyone must follow, not mattering his personal circumstances. Each student must observe his situation, what he needs and lacks and so on and so forth and then adequate the practice to his own life in a realistic and workable fashion. When doubt arises, one clarifies it with the lama, senior instructors and so on, depending on the case. There are so many different practices one can help oneself that in fact it is a matter of choosing what is best for each case. The methods available are so vast that I feel we aren't in lack of anything, even ngöndro, that a student can perfectly decide to perform if such is his will; it just won't be forced upon him as a prerequisite to other methods. It's really simple and I never understood why there's so much fuss about it.
I completed ngöndro and still don't think it should be absolutely mandatory for everyone. Some people I know very well practice(ed) ngöndro with the purpose of getting done with it to move along. Some even admit such in private. They didn't start like that, but in the end they just want to finish it. Their fault? Perhaps, but not everyone has access to good teachings or teachers. So slowly they go from enthusiasm to the point when they slowly slip into performing it quite mechanically, bored and without having their heart in it, even when up to a 1/3rd they were apparently doing fine. But as it is a prerequisite and they have no time to do it under retreat conditions, they never really connect deeply with the practice or really experience any stable or consistent progress.
Their mind is untamed, without meditative stabilization, and instead of stabilizing it through correct practice they work out the prostrations, trout the poorly understood sadhana, do the respective visualizations imperfectly, perform mudras and offerings without really engaging the spirit of the practice and end up quitting or taking over 20 years to finish. The freaking ngöndro, more than 20 years, and not because they are doing it again! This shows lack of commitment or connection to the practice. It doesn't take a genius to see something is wrong about it. Meanwhile, their mind remains as untamed as it was when they started.
It's not ngöndro's fault. They just have a shity life which doesn't allow them to practice properly and sometimes they don't even know it. So they "work out", sing mysterious tibetan phrases again and again, do funny gestures and small rituals that they don't understand very well and that's pretty much the whole story. Of course
some will say that they "feel" like this and like that in quite a new agish manner, but there are no signs to be seen, as expected. Mind untamed, emotions untamed, behavior untamed. This leads nowhere, as you guys know. So their mind remains untamed. If they engage in Yidam practice with that attitude, and some do, it will be the same old with the same results. I STRESS that it shouldn't be like this. This is not how one should practice when doing the preliminaries, let alone creation/completion stages. Still, it happens much more than most of us would like to admit. Had they spent all that time just practicing shamatha and simply focusing on the breath and then the inner signs along with vipashyana and they would have progressed much further in terms of taming their mind.
This doesn't address the necessity or lack of it of the tantric approach to Dzogchen. It addresses some of the different practitioners I've found during these years that struggled during many years poorly performing this or that practice simply because it was mandatory. Some of them are no longer Buddhists. They left thinking this was all wishful thinking, because after so many years of practice they were basically as afflicted and ignorant as before. What they don't realize is that probably they never performed a single session of ngöndro properly done, but this is not their fault. Of course my experience is very limited and I also know people who seem quite achieved following the traditional route.
Anyway, it's not because of the above that I don't think ngöndro is fundamental, but I've went about it before so I won't go into it again.