The premiership is on the verge of losing their 4th place in the Champions League they just about scraped by and earned enough co-efficient points in Europe this season by virtue of Liverpool reaching a final and spurs doing ok.
A bad performance in Europe next season would see the premiership lose a place in the champions league the season after making it harder to qualify for everyone including your own team.
Not supporting any other English teams in Europe is counter productive,short sighted and frankly a dickhead move.
http://www.espnfc.com/uefa-champions...s-league-place