Maybe you are to smart for me.
But the other reason is very simple why I use a free e-mail provider.
On public / hobby fora, usually they are not always proper maintained, because webadmins do it as a hobby, so that poses a risk that my real e-mail will be out in the open.
Even big companies sometimes throw your stuff out in the open.
But not being able to combat the spam problem, strengthens my believe that I need a free e-mail carrier, because of the above reason.
I will not fight it anymore and just, let it happen, because I cannot persuade you. To bad.