I'd encourage you to learn more about training.
First off, you don't seem to understand that the main focus of those ski racers sitting on a bike ISN"T to try to increase their VO2 max. At the elite level, it is nearly impossible to get a meaningful increases in VO2 max. This is a basic point. A VO2 max workout also doesn't involve sitting on a bike for hours. VO2 max and lactate threshold or LT are two very different things, and what those ski racers are focused on is lactate.
You also don't seem to understand why the term anaerobic threshold isn't favored anymore. It is part of the Wiki definition, still, for those who rely on that, but in the real world, there is no point where you "switch" from predominantly aerobic to predominantly "anaerobic" metabolism in something close to a binary fashion.
For those interested in actually learning more, give a Google and see that there are actually several measures of LT, and, while FT or FTP (functional power threshold/functional threshold power #) is close to a synonym, it's not an exact one, because FTP is roughly where you can sustain output for a very unfun hour. The way that connects to ski racing is in fact the work on a bike that the best racers in the world are putting in, so that, in preparing for their races, they come to be able to put up pretty good sustained #s in a way that often compares well to bike racers.
I knew that HIIT training was going to come up, and, along with a related approach to bodybuilding, both of which have been around for quite some time now, the reason they're periodic fads is that they can give quick results to untrained individuals for a while, followed by a plateau or even decline in performance and a high risk of injury. And, there's a good reason why ski teams out there, to take one example, aren't all dishing out HIIT workouts to their athletes.
Consider that many of the trainers of those athletes are very well-read in things like HIIT. And, often don't do them at all. The closest they may come is some type of power intervals.
As this relates to recreational skiers wanting to prep for ski season, if they really believe that their skiing is characterized by intense output that they can't sustain for more than a minute at a time, followed by a lengthy recovery period, with only a few runs possible in one day, then, for them, perhaps their skiing is close to as "anaerobic as it gets" and they should train accordingly. If they find that they actually take more than 10 runs and that, even at fairly small hills, those runs are often several minutes in length and that they are able to carry on a conversation with their friends when they get to the lift, then, hmmm, maybe their skiing ain't all that anaerobic, and, if they want to prepare for skiing and even be able to ski harder and longer, they may want to train accordingly.
Translated into ski town terms, there's a reason many strong locals don't lift at all, or do anything resembling HIIT interval work, but MTB, hike, and overall stay active, and manage to have a fairly seamless transition into ski season. Even those working the golf pro/ski instructor cycle generally move into the season without too much difficulty. If skiing were in reality something that for most involved very intense bouts of exertion of 1 minute or less, that wouldn't be the case.
You are obviously an intelligent individual. I don't want to stir the pot, and I hope my following statement will reflect that.
I think it's important to understand that just because the "best" racers in the World are training a certain way, doesn't mean it's the optimal or right way. A few years back I listened to Mark Rippetoe interview John Wellbourne (Ex NFL player, now trainer) about the training practices of NFL players. You would be surprised to hear that like skiing, the methodologies were extremely polarized and varied. At the World Class level, it really doesn't matter (as much) what athletes do. Wellbourne was discussing how some of the guys merely performed pushups and crunches their entire careers, yet still could squat 500 on demand without ever squatting one time. World Class is World Class.
We also need to be careful (myself included) that just because I have seen spectacular results training skiers using mostly Anaerobic methodologies, that I don't adopt a confirmation bias and therefore develop any premature cause and effect relationships. Furthermore, just because I know that I am right on this, doesn't mean you're wrong in your assertions. Nonetheless, it seems silly to argue that the best method for training skiers is through aerobic systems (not that you are necessarily making this argument). I don't care if the most decorated coach in the world suggests otherwise. It's fairly black and white that skiing, recreational or not is classified as a rather short, more intensive effort followed by sitting on a chair for 10 minutes. Aerobic training would have some benefit as it relates to recovery, but let's not get carried away.
Lastly, I am going to open a can of worms and argue that skiing in particular hosts a very large infrastructure of egotistical maniacal fools that will argue until their red in the face that the sky is purple, or that biking is great for ski training purposes.