Sure, but law and regulation doesn't work that way. It's about the intent, not the technicality. That's e.g. the difference between gross negligence, manslaughter and murder, even if someone died in all these situations.
The (IMHO bogus) argument Schneier was making was that it muddles the morality of the situation, not whether or not it is or isn't, or should or should not be illegal: just that it would invite "meddling" (his word).
For most people, it does. I hold political free speech protections as sacrosanct. I do not have the same view towards dark money.
Putting my views and morality aside, the law treats commercial and non-commercial speech differently. Integrating payments lets the government subpoena records (and more) under AML/ATF law. Those laws are powerful and broadly supported.
Totally separately, if we take the position that money is speech, then fine. Why the hell not make a one-click “send wallet address” option for a variety of coins?