Would it matter if it did? Would it change the addictive nature of either substance or the damage they do to people's lives? (and I speak as a legalization supporter)

Sounds like an ad hominem attack by impeaching the motives of the speaker. The implied message is that the speaker is biased against cocaine much more than other drugs so his judgment is not to be trusted.

Not such a good tactic.

EDIT: If this was an honest question and not sarcastic I apologize for misreading the tone. The internet is a tough medium for nuance.