I, personally, always make a custom build for every champion I buy and learn. I have always received compliments for the way my builds tend to work, but I have also had those kind of players in my matches.

Just ignore them, let the numbers speak for themselves

Still, sometimes at my Elo I hear:

WRIGGLES ON AD CARRY MAN? THAT SUX!!

Q_Q

You build boots of swiftness on supports. I don't see much of a problem here.

There is a bit of a grey area in regards to "correct" builds.

If i'm in a normal game and someone builds Ashe and rushes Swiftness Boots & Zeal then while I may think that is a poor build I'm not going to say anything. Clearly there are much more optimal builds but whatever.

Now if someone is Garen rushing Sorc Shoes & Deathcap then that is not acceptable in my mind. There is no rational for that build and it is just trolling whether intentional or not.

The game as a whole would be better without ranked and IP rewards, I remember playing for the sake of a good game, you tried to make it last and get the most out of it, and if a foe DCed, it was common courtesy to pick someone to leave that whay the rest could enjoy a fair challenge.

At one point I even think there was a way to swap allies... maybe I dreamed that part, but the point is, there was a time when the genre was enjoyed for no other reason than the challenge and immersion... To bad we can't fit that into LoL... "Better win n don't feed!"... So much for GL HF...

I've seen people like that in BOT games. Don't let it get to you. There are snobs everywhere.