The one stat Bledsoe is superior to Fouts is interceptions.
Granted, that's a crucial category, but as someone pointed out, the passing game and its rules are much different now than in the late 70's.
In Fouts' day, it was a rarity for a passer to get to 4,000 yds, and he did it 3 consecutive years, and would've done it possibly 7 or 8 years if he'd been healthy and there wasn't a strike in '82. And Bledsoe's career avg. passes per game is much higher than Fouts', so that's not a legitimate argument.
To me, the most important QB stats (not including won/loss record) are yards per attempt and passer rating. Fouts average ypa is over 1 yard more than Bledsoe's. In fact, Bledsoe's 6.6 ypa is one of the worst among the league's top 50 all-time passers.
Bledsoe's all-time numbers are a testament to two things: he's stayed healthy and he throws a lot of passes. If I'm not mistaken, Bledsoe has thrown more passes per game than any other QB in NFL history who has had any significant playing time. Not even Marino averaged as many per game.