I'm not sure on what constitutes a more dedicated approach, though I do think I know what your getting at here Shergs... The fact that Bolt & Ronnie appear to come across as a joker, not taking their sport seriously, or even wasting their talent, is a front but could come across as not really trying in some peoples eyes... But...
I've Never seen Bolt train but had the very good fortune to sit and watch Ronnie in practice, and trust me he puts in way more hours on the green baize than he lets on. Just one look at Bolt seems to suggest that the bloke isn't eating Maccy D's in the off season, out drinking and partying all of the time and to me shows that he's as dedicated if not more than most of the chasing pack around him. You simply can not stay at the top of your chosen sport without sacrificing something in your life. He used to practice at Scotties in Liverpool, a very well known club in the area, even put his own table in to boot. And before every UK Championship at Preston & the Worlds over in Sheffield would practice there relentlessly. That's where he came up with trying to go for a 147 left handed to challenge himself as he played that much he had to break up the sessions. I also know Les Dodd who tips his cues for him and he'll tell you that the only bloke who practised more than Ronnie that he knew was Stephen Hendry, and look what he won...
Also, when you look at the times in general of the sprinters, they should come down with age, you don't get quicker with age, matter of fact that really. Bolts fastest times did come earlier on in his career, as did most of the rest of the sprinters who have stayed the course with him. Maybe, and this is opening another can of worms here, the rest of the chasers arnt doing the drugs anymore so that they now have to train harder to get their times down. This now shows us that we may have a cleaner race and cleaner athletes in general...
Some sportsmen's talent is so natural it gets them to lofty heights, and I suppose it'll get you a long way. But to stay at the top needs dedication and commitment and that's what both Ronnie & Usain and most of the top,top players in the world have in abundance...
It has nothing to do with the fact Usain Bolt appears to come across as a joker. It is more to do with how he has spoken in interviews about how he hates to train, and the way a guy with his talent has performed in these world championships at the age of only 30. Justin Gatlin the winner was 35 just to put things into perspective a little.
I probably think a lot of what you say is true in regards Ronnie O'Sullivan, I think he likes people to think he doesn't care, but in actual fact he probably does care more than he lets on.
I think in Usain Bolts case it is different though, I think he has just possesed so much natural ability that after he broke those world records at the age of 22, he's kind of lost that drive to make himself even better.
To say that 100m runners get slower as they age is nonsense, perhaps once they are over 30 it is true, but it is not the case when you are 22. Most previous world record holders where a lot older than that when they set their best times.
I think Bolts dedication has just got less and less, as he's become more and more successful and that's why the times he was running have got slower, when usually a 100m runner would be getting faster from 22 onwards. He was just so far clear of everyone anyways, that he's still been able to win despite getting slower year by year.
I think the condition Usain Bolt turned up to these championships in proves he lacks that desire to win anymore. He could still be very close to his peak, if he had the desire to train. Let's not forget he's been beat by a guy 5 years older, so it's not a case of Bolt being too old to compete.
Can you honestly tell me that Bolt turned up to last years Olympics in the very best condition he could possibly be in, and did everything right throughout the year to make sure he did? Where he only just beat Gatlin on the nod. Or in this years world championships where he's been comprehensively beat by Gatlin.
I believe full well that if Usian Bolt really wanted it, he would still be winning the 100m now with ease. The likes of Gatlin and the rest would not get anywhere near him, even at 30.
I hope you don't take this as a criticism of Bolt, as I'm actually paying the guys talent a massive compliment. He's completely dominated sprinting for the best part of a decade in 3rd gear, and is one of the greatest sportsmen of all time. But I still believe he could have been even better if he'd wanted to be.