Maybe something to do with their, ahem, orange outfits? Not as flashy as the typical red, black and yellow. Orange only looks good on the Dutch women's field hockey, even the Dutch men's football team tend to stumble badly .......
As a matter of fact, LCW has been dominant in the Men Singles category for many years (46 career titles) - having being ranked world no. 1 since 2008. Hence, Chen Long should be perceived as the underdog here by discerning fans around the world. In any case, the trouble with your narrative is that when we apply the same situation to a sport that is historically dominated by US or the West like swimming for example and the recent London Olympics, we don’t see many people or Asians tending to be on the non-US side (even though the US is largely dominant in swimming) and cheering vigorously for China’s Ye Shiwen or Sun Yang. In fact, on the contrary (as if to add salt to wound), the British commentator, Clare Balding even questioned Ye’s incredible performance within seconds of her victory. Another top US coach even calls Ye Shiwen's world record Olympic swim 'disturbing' – alluding to allegations of doping. What happened to your professed people’s hope that non-western, Chinese or Asian swimmers can someday perform well in swimming? So my comment is not terrible at all – it is you who have been in slumberland all this while.
My 1GB brain proposes that the reason is more "political" than "logical". Y'know. .................... Peril/Threat stuffs (feel free to fill in the blanks)
it's easier for ROW players to win a tournament when china players underestimate it. All england is one of it. no wonder this tournament is loved by many players and their fans