i have a question

Because you are abusing the generosity of the person that gifted you the game.

It's not generous from you, if you want to be, get a game from your own money.

If your mother gift something to you in your birthday and then you give it to your friend how do you think your mother would feel?

Because someone made a giveaway for that game and you won it, by giving it away you are corrupting the idea of the giveaway and the ones who lost the opportunity to have it because you won it.

Because it's a site rule and by joining you agreed to follow the site rules, just like the rest of us. if you're not interested in a game, don't join that giveaway and leave it to people that are genuinely interested.

It was generous that somebody has made a giveaway and paid for this game, appreciate it and activate it on your account. It's not generous to give something you've got for free (especially when you don't need it, then it's just getting rid of unwanted stuff) :P