I hate to say this, but the Bruno Mars concert was basically the brainchild of the owner of the Hyundai Credit Card Company (HCCC), who is a brother in law of the Hyunda-Kia Motors owner who also attended the concert.
Obviously they are very wealthy, and they invited their own VIPs.
In addition, heavy users of the Hyundai Credit Cards got front end seats. Since it is the owner of HCCC who is holding the concert and Bruno Mars is just the performer, the HCCC owner can do whatever he feels like to the concert.
He just chose to put the entertainment figures on the front rows, to separate himself, the Hyundai-Kia Motors owner, and some people on the high echelon who get to enjoy first class view since they set up this event and just invited others who could join if they felt like it.
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I don't know much about BTS' 2019 concerts and the VIPs which might have attended there.
I do know quite a bit about the concert in 2022 , held by Lee Jieun, the former owner of Edam Entertainment.
Lee Jieun was the organizer of that concert, and not surprisingly the people in her coterie, like Yoo Inna, Kang Hanna, Jiyeon of T-Ara, Lee Joongi and some others (which included , not surprisingly now, Lee Jongsuk), along with figures like BTS' Jungkook, Twice's Nayeon, Jungyeon and Jihyo, Kara's Kang Jiyoung, txt's Beomkyu and Soobin, Viviz members, Kwon Eunbi, StayC's Sieun, etc put into a section of t heir own
However they were all put into section 24 or 25, I believe, two sections behnd the front section.
The front seats were reserved for the diehard Uaenas, those who supported her for all of her antics, misadventures and controversies.
It is just according to who the organizers choose to invite. Mr. Jung, the owner of HCCC, just chose to put his tycoon in law and their coterie, along with the entertainment figures , at the top, while Ms. Lee chose to put her coterie in the central sections 2 sections behind the front section , where she chose to seat her most diehard supporters.
There is no reason for salted Koreans to get angry - Mr Jung , who paid for the whole thing, has the rights to seat whoever he feels like to the best seats, and he did it. It's that simple.