How the game has changed has drastically altered how fans see QBs that played most of their career before 2000. People look at his yards, career tds, qbr, etc. and say wow most modern QBs are better statistically he must be overrated.
The no contact rule in the mid 90s made things easier for receivers and qbs as players. Then additional rule changes later on influenced more friendly passing attacks. For comparative purposes the average nfl team passes for 30 more yards a game over the last decade vs the 90s. The top QBs have delivered much more than that.
Though statistically Aikman looks overrated you could say the same for most earlier decade QBs, but he's 1 of 4 QBs to win 3 or more Super Bowls in his career and would argue a bus driver can't do that.