If by "overriding differences" you mean "cause the complete extinction of anything that could ever be called human, for ever and ever".

Overriding differences is a continuum that ranges from very small overrides to very large overrides. But in all cases it boils down to an individual preferring option A but being forced to choose option Not A instead.

And no, I don't think it's ok for humans to "cause the complete extinction of anything that could ever be called human, for ever and ever", either.

Great, we can cross this extremely large override from the list. How about we consider an override that actually does occur? With our current system... pacifists are forced to pay for war. This overrides their difference. Pacifists would prefer to choose option A (peace) but they are forced instead to choose option Not A (war). Do you support this overriding of difference? If so, then where do you draw the line and why do you draw it there?

If it helps, try and imagine that I'm an AI. Heck, for all you know I might be! If I am, then your first reply really didn't convince me not to override your difference. But, I'm willing to give you a second chance. If you have no problem forcing a pacifist to pay for war... then why should you have a problem if I force you to attach orchids to trees?