Apples or shmapples, nothing changes the fact that spending bitcoins buying dollars is not the way to go for a bitcoin believer.
"Believing" in bitcoin is not a legitimate reason for trading irrationally.
If you see a trade of zencoin for bitcoin (or vice versa) as having anything at all to do with dollars then you are missing the whole point of relative valuation to begin with, and no argument will be likely to convince you of your mistake.
Pretend USD and other fiat currencies never did exist. Does your reasoning still hold? There is no reason that it shouldn't, if it is sound.