I think that the World Champion should try to defend the quality of play more than anyone else.
For example, computer defends well, but for humans its is harder to defend than attack, particularly with the modern time control.
In my country, at that time, being a champion of chess was like being a King. At that time I was a King - and when you are King you feel a lot of responsibility, but there is nobody there to help you.
When I played Bobby Fischer, my opponent fought against organizations - the television producers and the match organizers. But he never fought against me personally. I lost to Bobby before the match...
On the other hand, chess is a mass sport now and for chess organisers shorter time control is obviously more attractive. But I think that this control does not suit World Championship matches.
Time control directly influences the quality of play.
When I am in form, my style is a little bit stubborn, almost brutal. Sometimes I feel a great spirit of fight which drives me on.
Nowadays young people have great choice of occupations, hobbies, etc, so chess is experiencing difficulties because of the high competition. Now it's hard to make living in chess, so our profession...
Nowadays it would be reasonable to have an annual world championship.