I agree with some of what has been said in here, but not all. Just because it seems like people are often kicking out of finishers, that doesn't mean that it is. The actual issue as someone kind of hinted at is that in TNA right now, the big names don't have just 1 finisher. They have several 'signature' moves that they use to try and finish the match, and 1 'final' move they go for when they need to put an end to a match because their other moves didn't work.
While it is true that there are a lot of matches that don't finish with the common finishing move, when they do hit the 'final' move, it does end the match somewhere in the 80-90 percent of the time. Most of the time that they are not successful is actually due more to outside interference then kicking out of someone's finishing move.
And beside while the moves are 'finishing' moves, and are supposed to end a match,it doesn't mean that they should be overly effective. That's the issue I've always had with the WWE. With the really big names, they often over emphasize the 'finishing' moves. Stone Cold-Rock-HHH-HbK. Their finishing moves are not really that impressive. A jawbreaker, a sidewalk slam, a face buster and a superkick. These are the four that for a few years their moves were unbeatable. Even Taker's tombstone was kicked out of when everyone was beat by Austin's pathetic jawbreaker. And you can count on 1 hand the number of times someone kicked out of HHH's pedigree.
A finisher, no matter what it is, needs to be used smartly and at the right time in order for it to be effective. And having someone kick out on occasion should enhance the match, not detract from the match. It's the same with submission moves and reverse/escape of them. Some wrestlers, like Angle, Samoa Joe and Jericho are considered submission specialists and their finishers reflect that. Yes Angle has the Slam, but his real finisher is the Angle Lock, and Joe's in the Kohime Clutch, not the muscle buster, but since both TNA and WWE have moved away from the submission style of wrestling, especially since the unfortunate incident with Benoit.
Back on topic,
Should finisher's finish a match? Yes,
Should people kick out everytime? No.
Do people kick out everytime, or even most of the time? No.
Do they do so too often? Yes, but it's not as blatant as a lot of people are complaining about.
A quick recap for recent memory.
Samoa joe-- Muscle buster, Kohime clutch.
Angle--Ankle Lock, Olympic/Angle Slam, Release German suplex
Sabin--CradleShock
Senshi--Way of the Warrior (top rope jump into double foot stomp)
Abyss--Blackhole Slam, Electric Shock backbreaker, ChokeSlam
Matt Morgan--Running boot, Hellavator.
Roode--Payoff(fisherman suplex pin, Mr Perfect's was perfect plex)
Dudley's--3d
Curryman--Spice Rack(a torture rack setup into a reverse death valley driver)
Storm--Last Call(his is a superkick ala HBK Sweet Chin Music, but a fallaway slam also used and called the same by JBL of WWE, storm's reference to last call at a bar, JBL reference is for stock market)
Lethal--Big Elbow(ala Macho Man and HBK), Lethal combo(think it's a backbreak flowing into a move like the complete shot face buster)
there are others but I think most of us reading this can name most of the rest.