Well, I agree with Timsmith the article was a tad incoherent, and also that some of the issues of 'shrinking' and graying are not so easy to quantify.
On the other hand I neither agree with the lack of diversity in wargaming production nor in the 'hardware fetishization' and the usual 'decline of hex and counter' tale.
On the first issue, there are some problems in either looking at BGG or at production runs. First Panzerblitz was a record seller, no doubt on that, hard numbers tell us this. But it is important to highlight also the context. Long print runs, more availability in storefronts, and less competition. Let's face the truth when Panzerblitz appeared it was revolutionary, and the other tactical games available were basically more or less its prototypes. It was the king of the field for years despite its mechanical problems (concentrating stuff against artillery fire?).
One of the issues in raw number comparison is that in the past there was a smaller offering than today. Sometimes you were buying games you felt they were so-so just because there was no alternative. Right now how many platoon level tactical game system are out? Simply comparing raw numbers outside context is disingenuous.
The sad truth is that we basically have no real idea, only anecdotal evidence on expansion-contraction of the player base.
As for the fetishization and hex and counters... well, Hex and Counters is by themselves limiting. Areas, point to point, and even squares are perfectly acceptable way to 'grid' maps... counters, well, even some of the COIN games uses counters... they are also better at displaying information than plastic stuff or cubes... I do not see traditional wargaming in decline. Even Bill's claim that 'non traditional wargames' outnumber traditional ones in 2020 seems, to me, only based on a cursory look at few publishers. I would even, is a side snipe, say that Colonel Bill's article are always a bit negative in this sense, he appears clearly happier with minis and screens... but it is just my feel
no criticism. If you look also at European publishers and also Chinese ones the numbers are probably opposite to the ones Bill's article suggest.
One thing that could be said is that gaming is diversifying. In the past there was a simple dichotomy (at least superficially) between 'hardcore' Wargames, and 'abstract' Euros. Now you have a new category of games emerging, let's call them Historical Games. They are poaching on both sides both as mechanics and players. Some are good, some are crap. Case study, IMHO, is the COIN series. I think it started quite well with Andean Abyss (see the review on my Blog , but then it devolved in crap and crappier. I found Fire in the Lake quite bad. I would not comment on Twilight Struggle, I think it is crap, but in the past one of my students did an excellent presentation on it. But certainly you have games that sits between different categories. Doing that they attract different kind of players. As anecdotal evidence, if you look on BGG a lot of comments on Fire in the Lake does not really address the game as a simulation but just 'game' aspects. I got the impressions that plenty (as in large but undefined numbers) of players does not care what these blocks represents on the map... Certainly these games appeal to gamer who are not too keen on the history behind, but keener on the game itself. Certainly some of their approaches are quite intriguing as game mechanics. Said that...
...Having taught, researched on COIN I feel these games are largely a simulation failure...
I also see a sort of bandwagon effect... they are popular and people cashiers on the idea, like after For the People and Paths of Glory launched a CDG mania... now CDG is a mechanic as others, and it has now been supplanted by the COIN as the new fashion trend. We will see if COIN is still fashion in 5-10 years time... Certainly I do not see it as inherently better at portraying counterinsurgency.
I also see a problem in the idea of symmetrical vs asymmetrical conflict. It is an empty dichotomy massively misunderstood and misused. All wars are asymmetrical. And we had wargames tackling different kind of wars from the start, some good, some average, some crap. Once I used both Fire in the Lake and Ici C'est la France in class. It is worth to note that some students said that at these levels counterinsurgency did not appears that different from other 'symmetrical' wars and would have liked to try more low level COIN gaming, like raids and ambushes. Of course raids and ambushes are something that had been done also in 'conventional' warfare... But it is worth to note that a group of non gamers, quite diverse in background were actually asking to see how hardware, doctrine, tactics, and training performed in actual combat.
I often say in class, wars are fought by people, with weapons, to achieve political goals. Ignore any one of them at your peril... both in war and research. Certainly one trend I do not like is the idea that focusing on military operations in a game is something inherently wrong (that was one of the lowest point on quite incoherent and rambling original article) , sadly this is something that some self appointed 'professional wargamers' seems to advocate.
Seeing serious, well designed and researched games covering not just wars but other historical events? Yes.
Marginalizing or eviscerating wargaming because a bunch of people do not like it and want something different? No.
Personally I do not see a decline in Hex and Counters (whatever this means). There are still plenty of good games, and they cater to a market and a need. What I see and think is positive, is rather an expansion and a creation of new fields. Games are powerful tool, and can be used also for exploring political events. But they are not wargames... and certainly are neither better or worse than wargames.
Personally will I play another COIN game? No, right now they have fallen into crappiness. Will I be on the lookout for other interesting subjects? Yes.