Some really interesting points in your article, so I'll see if I can hit at least some of them from my perspective in my response. As far as the "militant vegans", I think as is the case with so many different aspects of humanity, the squeakiest wheel gets the grease. Yes, many vegans are also activists, extremely passionate to be a voice for the voiceless, and some definitely rub people the wrong way. From my perspective, as a plant-based eater for the last seven years, I applaud anyone reducing their consumption even if they aren't fully vegan. As you pointed out, if more people do a little bit, it can have even more of an impact than the few going all in.
I forgot to look where you are from, but I can tell you here in Atlanta there is huge momentum behind the vegan movement. A local business called Slutty Vegan is exploding locally, and they've also taken their food truck all around the country with smashing success. They just opened up a second location. Both brick and mortar restaurants and the food truck can have lines where loyal patrons will wait 4 hours for a vegan burger! I can see them going far and wide in a number of years.
There's also a vegan pizza shop making waves, along with quite a large selection of other vegan restaurants that have been in the area for over 20 years. We also had the trial run of the KFC Beyond Chicken. They sold out in a number of hours, and again the line was down the block to try it. The demand is there. Just look at the big fast food chains and see how many of them have at least brought in a vegetarian or vegan option in the last year or two.
In my opinion some of the challenge in getting even more mass adoption to the plant-based options is the push back from the existing industries and lobbies. The dairy industry has tried to say you can't call plant milks "milk" and put a lot of money into trying to restrict usage of the term. That's only the tip of the iceburg. I don't even want to get into how embedded the government's food recommendations are in money and industry, either. As I've heard said before, there's no money in broccoli, so that's why no one advocates for it.
I think the marketing should hit all aspects of the benefits of consuming more plants and less animal products, as @springworth pointed out. For me the health research was what drew me in and spurred my own change, but then once I felt the benefits physically I started researching the environmental and ethical aspects and that has definitely had an impact in keeping me on the plant based train. Everyone responds differently to information. Some need the emotional link, where others are drawn by the science.
Though as a health advocate, I am also more of a fan of the veggie burgers actually made from vegetables and not in a lab. Give me a black bean burger over Beyond Meat any day. ;) But I think the mass produced options that taste remarkably like the "real" thing are such a great gateway to get people to try something outside of their comfort zone that is still, well, comfortable. Some people just want a juicy burger not a kale salad, haha. The more people give them a try, the more they'll realize how far the taste has come. Then maybe they'll eventually give the black beans a chance, too.
Great article and thanks for sparking some good conversation.