You seem to be arguing as if this is an all or nothing proposition. Instead there are definite degrees of intent and interaction here. In the E2EE case the degree of interaction and intent is quite low. In the mixer case the degree is quite high. The line I believe should be drawn somewhere in the middle. But the Mixer case definitely is on the wrong side for me.
E2EE is all-or-nothing. You don't see Matrix adding a special case in the encryption technique to notify authorities if the phrase "nuclear" or "minor" appears in a message. The intent of E2EE and Tornado Cash is exactly the same: privacy. The line you draw here is arbitrary based on your own subjective view of the space.
