I think that it's to symbolize that Thor has the power of odin
when thor got the odinforce why is it still called odinforce
I prefer to call it and for it to be known as the Odinforce.
It honors Thor's father and it tells a bit about where it came from. Thor has always had his own elemental powers due to being the God of Thunder. Odin was the All-Father of Asgard and it's denizens, and as such was nigh-omnipotent. With Odin gone and Thor inheriting his power it makes sense to still refer to this power as the Odinforce so everyone knows just how powerful he's become. Calling it the Thorforce doesn't quite have the same impact; for all anyone knows the Thorforce is only his previously mentioned elemental powers.
Thor with the Odinforce = Invincible
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