[TheDopp]

So you're saying that I can come back to WalMart after buying their bread, which is twice as expensive as Costco & a grocery store's bread, and then say "You sharked me with your prices I didn't know that. You scammed me now I demand a refund or I will sue you."

No, but you can not act like a douche and go "Hey, I want to return this as per your return policy."
It's also a stupid metaphor.
Sharking is scamming (and I know I'm one of only a handful out there to demand it be called that). Full stop, all cases. It's all about intent. You offer a fetti coupe on a burning TC, they take it, you're a shark if you knew the actual hat values, not if you're a trading noob and just thought their cool would be a good trade for your cool hat.
tl;dr - Stop whining and stop getting mad when people get annoyed with your lowballs and shark attempts even if they aren't lowballs or shark attempts.