I'm bored or I wouldn't be putting up any argument.
The poll question was "is tanking cheating?" If you take away the modifiers and leave just the one word answer, there are two "Yes" and two "No" options to reply.
While you're correct in assuming three options are "pro-tank" it's not what the question asked. I'll be so glad when April 12 rolls around.
EDIT: If we look at it your way, the entire poll is skewed towards tanking (with 3 of the 4 options being "pro-tank") and therefore not only invalid but misleading.