Just a theory (because I really have no proof of it), but do you think it may have something to do with the fact that you can't obtain Missingno the same way in an English version of Red/Blue or that Red/Blue is actually
based on the engine of the Japanese Blue, rather than of Red/Green?
For the former, my guess is based on the fact that during translation, if there's a known error in the game, the programming team might spend a bit more time working on the game before releasing the game to English audiences. (Or, alternatively, they'd simply rework the game so that points that can't work for English-speaking audiences are taken out.) This is why the glitches that were in the Japanese Gold/Silver didn't work in the English version of the same games and why Japanese Crystal had mobile capabilities while English Crystal did not. It could be plausible that during a making of Red/Blue (which was apparently already pretty heavily "reworked," what with the integration of Pokemon availability system of Red/Green being combined with the engine and graphics of Blue to produce the English version of the game), the programmers accidentally forged a new glitch simply by failing to remove the possibility of encountering Missingno but instead relocating it to a different portion of the map and possibly rewriting the sequence through which Missingno could be obtained.
For the latter, one would have to check Japanese Blue in order to find out the sequence of events needed to obtain Missingno, as if the English Red/Blue uses the game engine of the Japanese
Blue, then that may be a horse of a different color in terms of glitches, in the way English Red/Blue has a fairly different set of glitches compared to English Yellow.
But again, both are pretty much just theories. I could be completely wrong on either or both, but it's a start for a train of thought. *shrug*