I agree with your sentiment.....I am a soccer fan that hopes the Argos (all our teams really) do welll.....I have my doubts about how BMO Field will impact Argos attendance but will be happy if I am wrong.
That said......let's look at the flaws in this statement from the article you linked.
1. The question posed seems to be about CFL and MLS not Argos and TFC
2. CFL has had, what, 100+ years to build that support....MLS a wee bit less
3. The question seems to be "do you closely track"....not "will you go".....presumably that question would have produced similar numbers last year when the Argos averaged 17k and TFC averaged 21k (I know the premise now is that stadium will improve attendance but to conclude "It suggests Argos attendance will top that of TFC's on game days - a positive for the newly acquired CFL team." is about as flawed a survey logic leap as I have ever seen).
4. The bolded part is just plain ridiculous......in Ontario there is, exactly, 1 MLS team....there are 3 CFL teams. The fact that people who "closely track" MLS in the part of the province that is not Toronto is less than in Toronto is not a surprise at all. The fact that CFL numbers are the same in the province and the city is also not a surprise....people in Ottawa and Hamilton "closely track" the CFL.....yeah, they have teams in the CFL......but how those numbers translate to higher attendance at Argo's games is beyond my logic.
I welcome the Argos to BMO.....I hope they do well...I hope they do better than I suspect......but this survey/poll is so flawed it is laughable and its publication is just like the TFC supporters tweeting out pictures of the 1950 mud bowl....it is irrelevant and meaningless and, likely, just going to inflame the "debate".