From the article:
"I saw a few people on Facebook seeming almost unimpressed by Robles' national championship because of his upper body advantage, and because his opponents cannot perform techniques like the double-leg takedown."
some people are just so full of hate and jealousy for anything other have that they don't, it sad...
I used to wrestle for a perhaps somewhat longtime, and I can tell you this does give him many advantages, since he will be stronger than any of his opponents probably, and they can't use certain moves. When I was in high school, there was a kid from another school with no legs (great guy, by the way). His upper body was huge, and no one really knew what kind of strategy to use against him. Luckily, I never had to face him--different weight class.
However, the people referred to in the article neglect to mention that Robles and others are also disadvantaged. There are just as many moves that they cannot use because of their disabilities. So it probably evens out in that aspect. And he may have a stronger upper body, but he also does not have the ability to gain leverage like someone with two legs can, so that may even things out in that regard as well. The only real advantage I can think of is that he has more experience wrestling people with two legs than his oppoents, probably, have against people with one leg, but I don't think experience is an unfair advantage in things competitions like this.