The Yankees seem to be more pissed at the fact the Jays all but ended whatever slim playoff hopes they had, more than anything else. That this is getting play in the (national U.S.) media is just a reflection of the Yankees popularity.
It's pretty funny. One US analyst called the Jays a bunch of "little crybabies" but who exactly is crying about all this? The Yankees are the ones whining about the Jays swagger, the Yankees are the ones who resorted to childish taunts, and the Yankees are the ones who spent most of the 4-game set arguing with the umpires. In fact, Stroman's words ("Yep. That's a strike") -- that have courted so much controversy -- were directed at Sanchez after he got caught looking at an obvious strike and was arguing with the umpire over it. Maybe if the Yankees had an understanding of the strike zone, they wouldn't be getting shut out, what is it, 6 times in the month of September? By contrast, the Jays have, ironically, taken this pretty well in stride, notwithstanding the two injuries suffered as a result of the shenanigans.