People are jealous. It's as simple as that.
If they offered the trade, and you didn't solicite it, then it's fair game imo. You could have been nice and informed them, but in reality they should have asked around prior to trading or at least asked you if it's a fair trade.
As long as you aren't misleading them or lying to them...there is a reason I always tell people to ask first before trading.
Trading is risk, if you don't do your research before hand, you have no one to blame but yourself...
If you don't want to put yourself at risk, don't trade. Just buy packs and keep what you have.
And people like to throw around the word 'scammer' around when it isn't appropriate (Pet peeve of mine).
Telling someone Elizabeth is worth 6kte and Nina is worth less, is an appropriate time to call someone a scammer.
Stealing someones card after promising to return it, is an appropriate time to call someone a scammer.
Losing your pants because you didn't do research prior and massively overbid to someone, doesn't make the other party a scammer. It makes you, the one now standing around looking foolish in your underwear, gullible.
But of course it's easier to blame someone else rather than yourself. Preferable too because it saves you from the embarassment of telling people you were gullible and made a fool of...