True.
First of all, its nearly impossible tu say who is the best player ever, for various reasons. One of them being the fact that you cant compare football from fourty years ago with todays football. It has changed so much. And who knows, maybe someone who is playing today, with his talent, might have fit better into the style of playing football some decades ago and therefore might have achieved even more.
Or (im not sure if its true though) what about the fact that players of todays generation have to suffer from injuries more often than those in, lets say, the 60's? I mean, take Ronaldo for example, the guy was just great but look through his career and you see that he had some major inuries which prevented him from achieveing even more. And one cause for his problems is that football is so much more physical today than "football from yesterday". I hope you guys see what i want to say.
Anyway, there are probably a few more reasons why its so hard to compare players from the past and present.
With regard to my earlier point: I my opinion the vast majority of what we see in tv about those big stars from yesterday, are the positive, outstanding things they have done. But what about the other side?
If you follow football today, you actually know about the weak phases some players have and it changes the way you look at them. This opposite side is missing when it comes to your judgement about Maradona and Co.
Nonetheless, i dont doubt that Pele for example, is among the best players ever. Obviously.