I see your point, and I would understand if the feature is not implemented for that kind of reason. However, in this particular case, I think the probability that there will ever be an action starting with an "y" involving a door is vanishingly small, so I don't think it should conflict with anything in the future.
However if the devs consider this to go against code maintainability, I'll just adapt to pressing "o" or "space", it's of course not a big deal.