Janikowski is a good kicker, but he's nowhere near HOF caliber. Let me compare him to another kicker who is deemed good but who rarely gets much attention - Ryan Longwell.
Janikowski: Active 12 years (including this year), 262/333 (78.7%

Longwell: Active 15 years (including this year), 340/407 (83.5%)
Janikowski: 88/144 (61.1%) at 40+ yards
Longwell: 103/147 (70.1%) at 40+ yards
Janikowski tied the NFL record for the longest field goal made and he has the most touchbacks. And he holds (and will probably hold forever) the record for the longest field goal attempted at 76 yards and is one of the very few kickers to be drafted in the first round. But those are just trivia pieces that don't say anything about him as a player.
He's not really outstanding. Not the most accurate kicker - he's all about power. Longwell is a lot more accurate, but he rarely gets touchbacks.
The only dedicated kicker in the hall of fame (Jan Stenerud) got there because he basically reinvented the position, being one of the first guys who only kicked and didn't do anything else. So even having a long, reliable career probably isn't enough.
EDIT: Hell, Nate Kaeding is the most accurate field goal kicker ever and you won't see him in the HOF thanks to his ability to choke in the playoffs and take himself out for an entire season on the first play (lol).