You anger me, you said that you don't try to make other people's work look like your own, yet the only advice that you ever give is about light source, and blending, they are Not the the only two key features in a sig, there is so much more than that, Graphics is essentially a sub category of art, as such, graphics design is supposed to be artistic, we get to the question, "What is art?" art is method of communicating your own creativity, though the use of line, color, tone and all of the other formal elements, it is something that should represent you as a person, as such, a sig should be unique, it should be creative, it should represent the user who made it. This is a forum, not a business, if it was a business, then sure, your pastel colored tutorial copied garbage would be the right thing to do, but this is not a business, this is a contest of people showing their graphics creativity, not their graphics professionalism, and you tearing them down cause their work doesn't look like your own, is unfair, mean and un-called for.
You have no subtlety when it comes to giving constructive criticism, what you say is not constructive, it's destructive, you pretty much tell people to start from the ground up, i have yet to see you genuinely give someone a positive remark on their work, the only times you've come close, you quickly follow it by saying "That's only cause it's your first attempt, if you made stuff like this with more experience i'd rate it 0.2/10". How do you think that feels? to have someone pretty much tell you your s**t at graphics? It's not nice.
If your going to give CC, you need to be positive as well as negative, the idea of it being Constructive, is that you are helping them build on the skills they have, you point out the good parts, then tell them the parts they need to improve, you never do that -.-
Edit: @Hells: i sorry if this is in some way ruining your competition, i just really needed to get that off my chest, it's a good contest, i voted for the 5th on, Ramones are BA