I think the bigger question is, why do people feel the need to make up excuses because a segment of reviewers had a different level of enjoyment with a particular game? Why do we come across, "I liked the game but the reviewer didn't, so they suck," when we're talking about opinions?
Most of the time, generalized attacks on reviewers are just fanboy excuses. What they're really mad about is that the game wasn't given +10 for being an exclusive on their favorite console. That's not true all the time, of course, but when a dozen reviewers are complaining about something, it's probably a valid opinion.
As for the skill question, gaming now is a lot more variable, which I think requires more skill-sets. Certainly, gamers of the NES era would likely dominate in 2D platform play that depends on timing but they'd also get their asses handed to them in RTS or anything multi-player. It's just a difference of skill-sets, which are generally based on experience levels. Overall, because of the vast amount of genres available today, modern gamers obviously have a wider array of skills, even if they aren't as generally focused.
