Guess what, people? Title says it all: whether you bought the icebreaker from Xur, or whether you grinded out raids and nightfalls, you earned your icebreaker. And don't let any other selfish shit tell you otherwise. I shall explain.
If you GRINDED, you EARNED. Simple as that.
If you got icebreaker through a raid, you had to GRIND to get it, but also have to wait for RNG to bless you with such a gift.
If you got icebreaker through Xur, you had to GRIND to get strange coins, but also have to wait for Xur to bless you with such a gift.
See the similarity? It's the same thing ultimately! The only time I think someone wouldn't have EARNED their icebreaker is if you hacked/cheated it onto your profile somehow (or if you cheese raids all the way through).
And with that off my chest, I salute you guardians. Go ahead and have fun with your icebreakers regardless of method of ownership, and just let the infants cry in the corner as this debate finally goddamn dies down.