Now why exactly did Konami banned Hideo Kojima from attending the 2015 Video Game Awards? Also what were your reaction over that incident?

They did it because they wanted to take full credit on the creation of Metal Gear Solid V and didn't want Kojima to come, banning him from even coming to the event to claim his reward, which he followed for fear of what Konami would do (Most likely a huge lawsuit).
And my reaction... Well, it helped me see that Konami is a bunch of c****s. I'd say I hope they go bankrupt soon, but they make más than video games, so they won't go bankrupt. They'll continue to make stupid decisions and ruin franchises and we will just have to live with it, o burn the studio down ourselves :P