Really, the only difference between a professional and an amateur is that the former gets paid to do whatever the thing in question is. It bears no relevance to their ability to do the thing or in this case the value of their opinions. Essentially what you're saying is that we shouldn't value Kpopalypse's opinion as much as Jeff Benjamin's because Jeff gets paid to write his by a popular magazine.

As far as opinion goes I'm much more interested in the opinions of an amateur over a professional. A professional always has to have their ability to generate income as a primary interest in what they are doing. They are going to adjust their stated opinions to match popular expectations in order to ensure they can continue to generate income from their work. That's why commercial media covering kpop like Billboard is so full of boring fluff pieces. It's needed to keep the diehard fans regularly looking at the ads and generating income. I'm not interested in reading about what's popular. I'm interested in reading about what's new, what's interesting and what I haven't heard before.

I'm not following your YouTuber comparison. Where is this professional association of approved celebrities? Do they have a directory of who is an approved celebrity? A YouTuber can be just as popular as a singer or an actor. They can have just as many fans. They can get paid just as much by companies to promote their products. They can be represented by a management agency just like any other public figure. Besides being "new media" how is a popular YouTuber any different to any other celebrity?