The two have gone through drastic changes. That and 20 years is rounding up on your part, but I'll let your liberal use of the numbers slide.
Michaels, as a character, has evolved and changed. Michaels has been the Shawn Michaels of the 90s and come back as a different, better man. Shawn has become a man who had to be tempted or pushed to go to extreme lengths to hurt an opponent, as was the case in his feuds with Randy Orton in 2007, Jericho last year, and the McMahons in 2006. Michaels doesn't resort to the measures that would inflict great harm on an opponent as impulsively as The Game and Michaels is able to display the moral scruples left by his actions in an expressive manner. In addition to all of those challanges, last year we saw a somber Shawn Michaels who was weighed down by the guilt of what he did at Mania and the difficult position JBL put him in. The character has gained layers that Triple H's character hasn't. Hunter's character just does things and has never really been challanged like Michaels' beliefs and decisions have been.
As for Taker, he took a long break from his Deadman character at one point, is still really only a part-time special attraction most of the time, and doesn't hog the title scene in an uncalled for manner like Triple H.
That's why they get more of a pass than The Game.
Yes, Shawn and Taker went through some changes throughout their careers, but so have Triple H. He went from being a cocky blueblood, a funny degenerate, a pissed off cerebral assassin, a clean shaven arrogant leader of Evolution, a degenerate again, and now he is a mix of all of these gimmicks. Jake saying he refuses to change gimmicks is ridiculous, Taker and Shawn also had more time in the WWE than Trips, so of course they have more layers added on to their style. In the end, they are still the Sexy Boy and the Deadman, just like Triple H will always be The Game.
So Triple H should get a pass because Shawn sucks at this too?
I never did say Triple H is putting younger talent over from left to right, I admit that he rarely puts younger talent over, I am just pointing out the fact that Shawn and Taker rarely puts younger talent over either.
Oh, and Shawn put over Jeff and Jericho last year.
Shawn put over Jeff in a meaningless match, there was no storyline or feud to it, but yes, Shawn did make Jeff look good. Triple H on the other hand, did have a friendly rivalry feud with Jeff, and he put him over, even though the haters try to deny it. If you watch that match, you will notice that the fans went crazy over Jeff's victory, it may have been a roll up, but the fans didn't care, a win is a win. Like it or not, but the fans will remember Jeff's PPV roll up victory over Triple H before they remember that random match against HBK on RAW, I totally forgot about it myself until you mentioned it lol.
As for Jericho, he was already an established star to begin with, it's not like Shawn was creating the next big Main Eventer or anything.
Taker continued to give up and sell for Big Show several times this year and last year, suffering several clean losses he didn't have to take. He also put Kozlov over.
Like I previously said about Jericho, Big Show is already a big star in the WWE, unlike Brian Kendrick, who desperately needs a push.
Koslov's victory over Taker was nullified when Shawn and Taker beat him consecutively a few weeks later. They were instrumental in ruining his monster push.
Also, even though it did nothing for the man, both Shawn and Taker helped Kennedy out.
You said it yourself, they obviously didn't put him over good enough since he got fired recently.