The first two chapters of a spinoff manga telling the early story of Sinbad from when he was a little kid just got uploaded on mangahere.
If the first line of your blog description is “I’m better than you”, chances are you are a terrible person who deserves to be beaten over the head with a brick.
That aside, avoiding going on a rant, I’m going to make this short and sweet:
Everyone has the right to develop and hold an opinion, regardless to whether that opinion is positive or negative, or about a person or something that person does. That being said, that does NOT give you the right to be a complete shithead with your opinion.
On the same note, someone not cosplaying the way you want them to, does not give you the right to act like some entitled ass who is the greatest thing to ever walk the earth in a costume, doubly so if your ‘great, totally canon costume’ is comprised of things that can be bought from two websites. If you don’t make any part of your costume, you don’t deserve the right to call yourself a great cosplayer, and you certainly don’t have the right to criticize anyone else on theirs. Even if someone makes the worst t-shirt in the world, they still put more effort into their costume than you, and that immediately makes them a better cosplayer than you.
tl;dr: Just because you get a few notes on tumblr doesn’t make you a good cosplayer, and it certainly doesn’t make you a good person.