No it isn't, maybe it is in the one day game, but not the test arena. Things go in cycles, we lost one ashes so apparently winning 4 of the previos 5 counts for nothing? Not for me, we've gone through our best period of cricket since Beefy retired (maybe even better)with the "methodical plodders" of Cook and Strauss at the helm. I'd put our problems much more down to the end of an era of a lot of players than the style of cricket. We had a great generation, then we suffered as they all aged together and declined/retired, now we look to start up a new generation with the likes of Root, Stokes, Wood and the like. Players win matches, not the "brand of cricket".The methodical plodding of our test cricket is the reason we fell behind the southern colonials in the past few years.
I'd point the finger far less at the style of play and far more at the passing of time. (much like for Australia when their golden generation declined and twe got the upper hand)