Have you seen that "poll" on the opinion of Iraqis on Alqeda? The biggest deterrent is social ostracism. Enforcement with consequences also reduces the lure and appeal of antisocial activity. There are many things one could threaten a suicide bomber with. How about a Vengeful Virgins vendetta? :)
You're half kidding, but you're right on the money. Most fanatics need the approval of their society to do something like this. We know that names of martyrs are celebrated as brave Arab resistance fighters, and that their families are generally given great prestige and honor (and often cash) when a shaheed blows himself up.
Even though the host governments where these people are recruited punish those who would openly advocate it, in many cases public opinion is firmly behind the bombers. Even state controlled Arab media semi-unintentionally plays into this, by casting Americans in a more negative light than suicide bombers.
Psychologically, one of the things that's a common thread between the average suicide bombers is that they felt unimportant and helpless back home, and feared they'd never amount to anything. Being a suicide bomber is the only way these guys felt they could ever do anything and be remembered by their people as having attained true greatness.
So, you're exactly right. If these people felt that they would not be remembered as heroes, but as villains, they wouldn't do it. They thrive on the moral support their communities give them.