Apparently 4Minute was only given 10 minutes of actual promotion time during the entire show. When they weren’t the center of attention, they merely stood in the background while the show continued on as normal.
Of course Korean netizens were a bit pissed off. They thought 4Minute should have received much more respect as a popular idol group. Some even sent messages to 4Minute telling them to return to Korea where their native fans would give them tons of love.
IMO: You can’t expect the J-pop industry to just roll out a red carpet for 4Minute just because they have gained a bit of popularity. Foreign acts in Japan normally have to prove themselves and rise through the ranks before they are given full attention on television shows.