Keep in mind, that TSA has yet to have stopped a single bombing. The only reasons we've not had a plane go down is due to lack of effort, not any increase in security. The few attempts that have been made, made it through the TSA with ease and it was the efforts of passengers or the stupidity of the attacker that saved the plane.
The famous "few attempts that have been made" originated in foreign countries, not in the USA. You admit that there is a "lack of effort". Huh. You'd like us to believe that this is because "teh TSA am stoopid" or something that amounts to that, but in fact it very well could be that the bad guys have decided that the likelihood of getting a bomb on a plane is not "100%" or close to it like you seem to believe but quite a bit below that. I'd say maybe a 5-10% chance of getting through security successfully. Suicide bombers are a limited quantity and the chance of failure could be a disaster because if the would be bomber gets caught by the TSA, the US government now has access to the type of bomb being used and may be able to get the failed terrorist to talk. This is exactly what happened with Richard Reid.
People have car alarms not because they believe that it makes their car impossible to break into but because it raises the bar so that it may be more trouble than it's worth. Actually I think the TSA is working because if it was truly as bad as you and other complainers claim, there would have been a successful attempt already. I think the bad guys have decided that the risk is too high that they won't get away with it and the success would not be worth the risk of getting caught.
I wish I could find out when the last time is that you even flew to/from/within the USA. I had a friend a few years ago who would go into a full blown hissy fit and rant about the TSA, making pretty much the same arguments as you. He last flew around 1998 and he is very likely to never in his life get on a plane again. It has nothing at all to do with the TSA - he has no reason or desire to ever travel by plane. Yet from all his complaining you'd think that he was some kind of hard core road warrior who was at a different US airport every week. I have found that in general the people who complain the most about the TSA are the people who fly the least.