It does not answer the question, instead it quells an inner doubt you may have if you feel like your team just did something stupid.
Please stop throwing out red herrings and say it can't possibly be true, for the only people who are arguing it may gain from the situation.
----
1) Is the argument falsifiable yes or no?
2) If it's not falsifiable with current techniques, is it plausible?
Now with 2 there are often competing arguments you then have to look at the specific weight of evidence, but just saying a person may have a motivated reasoning does not prevent them from making a valid point, the truth may be on their side even if they profit or if they do not profit.
When you start seeing a person as an enemy in a discussion you invite bad faith in the discussion and once there is no longer any good faith you have two people arguing past each other.