Why superstars are special?

Of late, I had become skeptical of the iconic status being accorded to some hyperactive overacting superstars like SRK and Big B. However, I amused myself by saying that they are reaping a harvest from their glorious pasts. Yesterday, I got a glimpse of that when i was watching Amitabh Bacchan's flick. 'Namak Halaal'.
The artificial and overconscious Amitabh of taday with a made-up baritone voice is a far cry from the sponteaneous, jovial and natural genius that he used to be in his heydays. He is well past his prime insofar as his natural genius is concerned. He can find a kindred spirit in Sachin Tendulkar who is still in awesome touch but the world rues the loss of his reckless youth.
Talking of 'Namak Halaal', Amitabh was at his comical best. He made us realise how his presence overshadowed that of any stand-up comedian. It goes without saying that he made many comedians jobless because he was able to enact simply anything. The starting of the movie is in itself a different one in which a fantasising Amitabh is awaken from his slumber by his daddu and he reacts in a novel naive way, "Daddu tum?".
The genius reflected again when he almost recited a cricket commentary in front of the villain Ranjit. The flow was awesome, barring the made-up vernacular diction, and the problem was that there seemed to be no grammatical mistake in his commentary. This is how lives are in rural India where good speakers are not kept to the pedestal because they do not doff their uniforms.
Analyse this. The morphed Amitabh has become Big B and is now a commercial actor who probably overdoes everything from advertising to acting. His performances still remain forces to reckon with but in no way are they naturally driven. There seems a management-ish perspective lurking behind his acting nowadays. He is now a brand and that has killed his natural genius. His peformances in KKKG, Mohabbatein, Aks, Ek Ajnabee, Viruddh, Baghban, Lakshya etc were all godd but still not fitful for a person like Amitabh who could sway the audience earlier by his 'real' voice and liguistic skills, esp the command on 'Awadhi'in a market full of bhaiyas.
I reminisce the legend Dilip Kumar giving up to overacting is his later years.The sober Yousuf Khan from the former frontier estate of Peshawar created ripples in Bollywood with his most natural acting skills in various movies like Mela, Amar, Madhumati, Andaj, Devdas, mughal-e-ajam et al. He unfortunately met decadence in the later years with a developed propenisity for overacting in movies like Karma, Vidhaata, Suadagar and many others.
The living legend SRK is still painfully manifesting that. Who will forget the awesome protrayal of Mohan Bhargava in the movie Swades? It required a staid direction by Ashutosh Gowarikar that brought out the latent best in SRK. That is also the SRK we pine for. We got to see a tad of that magical touch in Chak De. Contrast them with his unnatural albeit commercially succesful performances in candyfloss tearjerkers like Kuch Kuch Hota Hai, Dil To Pagal Hai, Mohabatein etc.