This is partly OT, but bear with me - I have a point that pertains to WC, I think. (Or I'm just rambling. Always a possibility.)
One of the issues I see with that Aikidoka's responses is that I don't see the "jujutsu" (as Kondo Katsuyuki would refer to it) from Daito-ryu - something I don't see trained in most of mainline Aikido (I expect it shows up more in Yoshinkan, possibly in Shotokan/Tomiki). I see him trying to apply the "aiki-jujutsu", which happens at a fairly specific timing. When he misses that timing, he just keeps dragging into the same technique. With just a couple of close-in techniques and some practice on the non-aiki side of the techniques, he would have had a much easier time of a couple of points in that.
So, how does this apply to WC? Well, much of Aikido has a very heavy focus on the single principle of aiki. Aiki takes precedence in at least most of the training I've seen in their mainline - precedence over effectiveness. It becomes an absolute, rather than "best, when available". So, they practice using attacks that make it available, and work to find ways to make it available in other attacks. From some of the discussions I've seen on WC, it seems perhaps some of this same process has happened in that art. There seems to be an absolutist approach to some of the principles.
The principles are guidelines on how the art works, but should not restrict from alternatives. I don't know the WC principles well enough to use one as an example, but you guys can probably translate this to your art. When I'm teaching NGA, aiki is still a primary principle. It's still "best, when available". But I also teach force-on-force options (hard blocks that jam the momentum, big strikes) and push-pull responses (more Judo-style). Why? At the very least, they are fixes for when you screw up. Equally importantly, sometimes they are better answers than the "aiki" answer. They still fit within the overall principles of the art, but the "aiki" principle doesn't get to dictate our every response. Effectiveness is the primary principle.
Again, back to WC and the discussion at hand. Competition and/or sparring between lineages can bring some of this to the fore. People see a grappling move from a line that sees WC as grappling. The folks who grapple more occasionally see a striking sequence or tactic that defeats them, and they adjust. And someone who trained in something else (as well as their WC), brings in a different step, stance, posture, or punch. It's not purely WC, but it fits nicely, and someone else decides they like it. Effectiveness starts to help evolve how WC is used, and how the principles are implemented.
Again, all this is just my view from the outside, based on what I've heard discussed in this thread and the couple dozen others I've been involved in.