Among other things it just makes sense as you can build into doing extra kinetic damage on chilled targets and the glaive does kinetic damage. Glaives aren't awful but being honest they aren't worthy of taking the place of most energy weapons.
I really want to run a glaive.......... But there are just so many better options for that slot.
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Glaives are really best in Gambit. They are too risky in highend content like Master or Grandmaster nightfalls cause you don't want to be that close to an enemy and I agree that for everything else PVE, you wanna rock like a shotgun or something. But in Gambit it is super fun and they -blam!- slay.