mixing : drag and drop

I had a google but could not see a similar topic
Anyways in the mixer

If I drag a insert plugin from track A to track B, it moves it, thus track A is now empty (if I want copy I need to hold alt)
yet if I drag the EQ or the inserts (as a group), it does a copy, i.e. leaves track A alone (if I want move I need to hold alt)

why the non uniform behavior? Surely over all the interfaces it should be the same .
eg click & drag = move, click & alt & drag = copy, whatever but surely this should be uniform.

Its not a big issue but it seems a strange behaviour