After a slow and inconsistent Season 5, to dismantle the passé dynamic of 'Damon (Ian Somerhalder)/Elena (Nina Dobrev)/Katherine (also Nina Dobrev)/Stefan (Paul Wesley)'s' entangled web of love drama was a strong move. It further indicates why Katherine simply had to go.
Don't get me wrong, it's not for the lack of love for Katherine- quite the opposite. Regardless of her unquestionably evil core, she has been an extremely colorful and engaging character; but I'm sure you agree that the perpetual lacklustre love storylines were beginning to give off a stagnant stench of writer's block.
As Hollywood life explain, March 6 saw 'the Mystic Falls gang finally get the best of her' and thus put her down, though in a slightly merciful way (ie. in Paul’s arms.) This was a situation made somewhat better by the boss Julie Plec whose henchmen helped her drag Katherine into the pit of hell.
As Hollywood Life explain:
Everyone in the freaking universe going after Katherine (and somehow failing — even Klaus!) was beginning to feel completely tired, repetitive, and unrealistic.
So with the next villain waiting to pounce into action, all I can say is as long as we don't have to endure another character like Katherine who was stunting the show, then from here, it's onwards and upwards. So See ya Katherine! And make sure you keep those boring and laborious storylines buried in the depths of hell with you.
Do you think that killing off Katherine was a good move?
Killing Katherine was
Source: Hollywood Life