I mean because nicotine might be protective against the coronavirus, and that protective effect might outweigh the harm of vaping. Certainly not proven (and please nobody start vaping because of that), but there's some weak evidence and it's funny.

Of course vaping's real benefit to public health comes from smoking cessation as you say, since smoking is (per my comment above) really deadly. I was disturbed to see the public health authorities blaming nicotine vaping for the lung injuries last summer, given (a) the ample evidence for vitamin E acetate as the cause; and (b) the cost in mortality from smokers who got scared by their misleading warnings and either didn't switch to vaping or switched back to cigarettes.