Actually despite Chen Long's 'unpopularity' in China for having lost three team majors - the two Thomas Cup and one Asian Games for which he receives a lot of brickbats and been called names, eg 'team insect,individual dragon' - he still has a significant following in China and in other parts of the world but nowhere near Lin Dan's, of course.
After Chen long's rousing success at Rio'16, Li Yongbo disclosed he deal with CL different from the way he handles Lin Dan whom he sometimes scolds, quarrels and even threatens if he is dissatisfied with his performance. For CL, he would not talk to him immediately after his flops but leave him be for a while and then talk to him nicely, encourage and even commiserate with him, nothing harsh.
Generally, it may be true Chen Long is not the kind of sporting heroes that have a wide appeal unlike his famous compatriot Lin Dan whom is regarded as all-conquering, all-winning, imperious on court, the 'I came. I saw. I conquered.' type, most fearsome, intimidating and dominant as in his heyday.
But Chen Long's appeal is of a different kind. His is a public persona that is very likable, agreeable, a softer image, endearing, adorable in a kind of way, sort of childlike innocent look. If I may illustrate, as when 1) he was faulted for serving above the waist and how did he reacted in protest? He tucked in his shirt in a gesture to the service judge to see clearly where his waist is while smiling wryly all the time, or 2) he was outfoxed at the net by his opponent, then affected an innocent, helpless look before giving his opponent the thumbs up, or just look at how he usually celebrates his victory upon winning the final point (I won't attempt to describe it in detail, go check it out yourself) , nothing in-your-face or outlandish but overly emotional he was as when he fell to his knees, went limp and crying like a child but shedding tears of joy while his coaches try to 'console' him and couldn't help grinning as they helped him up at the same time (recall Rio'16 final, WC'15, WC'14). To me, that look of seeming disbelief on his face when he just won the big match scoring the final point is priceless.
No matter what, one thing is for sure, which coach would not gladly have Chen Long ? Imagine if Chen Long could offer his services to any other MAs, I can safely and confidently say, all the Head Coaches would be falling over each other to get him. Bet my last dollar on it.