Rodney Harrison missed a lot of Pro Bowls because he was universally considered a dirty player. The
media hated him, opposing players thought he was dirty, hell, coaches thought he was the
dirtiest player in the league.
A guy like that doesn't make Pro Bowls, but you hope that history gives fans a different perspective. Since they began getting tracked in 1991, only Brian Dawkins (36) and Rod Woodson (20) have more forced fumbles than Harrison (16). His 1,242 tackles - and 950 solo tackles - place him 2nd all-time among safeties post merger.
Harrison's 34 INT's is 59th all time post merger (among safeties), but that obviously doesn't tell the whole story. Harrison - like Polamalu - was a strong safety, so he obviously didn't get the chance to roam like many other safeties that top the INT list did. Instead, he was camouflaged by lining up all over the field, and was really unique as he was one of the few safeties that could excel at blitzing. His 30.5 sacks is the most all time by a safety, and I believe the next closest safety would be Carnell Lake with 25 sacks. Either way, if you think Polamalu is worthy of the HoF, I'm assuming Harrison's 34 INT are a perfectly acceptable number (2 more than Polamalu).