To be fair, I think that more of the issue lies in initiative advantage rather than with Demolisher. Demolisher (without initiative advantage) allows for a single attack to be made before the target can react, whilst initiative advantage itself allows for 2 such attacks. This is why my example targeted initiative advantage rather than Demolisher itself.
Whilst the combo which brings this to light is Demolisher with initiative advantage (for a total of 3 attacks), I do wonder if people are focusing on the wrong issue by trying to counter 1 of the attacks rather than 2.