At the very least, these title edits should be opt-in where user use given options and supplied with the related reasoning — not just automatically done without warning.
I'm also unsure of whether this is a good rule, but it's one with an easy workaround. As another poster mentioned, the solution is to just edit the title after you submit it. The "How" removal only affects the initial submission. Subsequent edits aren't subject to the same automatic rule.
I think it's the worst feature of HN. This is a good example of a title that becomes far worse when "how" is removed, IMHO.
I hope this feature gets canceled.