Full disclsosure, Greg's a friend and regular shooting buddy. So personal bias admitted... I think there's more to it than what may only be seen from what one competition can show in the results.
We all know Top Shot is a reality show first that focuses on drama second and involves shooting third.
Greg is newer competition shooter. He was pulled onto the show as a Federal Officer. He has competed in USPSA for less than a year and is B in production now. He is also brand new to 3-gun as of late this year. In the two matches he's made it to in recent months, he was using borrowed equipment. He only started reloading a couple months ago!
It's not to say he is going to be a GM or should be cleaning up at 3-gun matches any time soon... but I don't think he deserves the performance based hate either... there's plenty to learn in any of these games (IDPA, Steel, USPSA, 3-gun, etc...) One can be a good / great shooter, and still have plenty to master in the rules of the game, the gear, the gun handling and in the art of reloading for competition.
BTW: To Viscusi's credit, she is not a competition shooter at all until very recently. Her desire was to be a model. She just learned through Top Shot that she had some untapped potential. If sponsors want to pick her up, who can blame her. The story I've heard is that JJ scouted her out at local matches and took his thoughts back to Glock. Glock and her then started talks... rest is public info / history. She got noticed because of her apperance on TV combined with looks / personality - no question. However, she has also taken to learning the sport of USPSA because she enjoys competition and shooting. She has had some successes and has been progressing through to top C in her local USPSA circuit. Word on the web is with the sponsor and JJ behind her (no pun intended) she will be traveling to various area, sectionals and larger matches in 2013.
I don't blame either one of them for trying to make a career out of shooting, obtaining sponsors and milking their 15 minutes of fame for all its worth - wherever it takes them. If they can turn it into a full time shooting career, and progress in the game while they do it, and it helps the companies sell more product, more power to all involved.
Anyway, just my 2 cents,