Understanding The Isolani Pawn After reading Chess structures of Mauricio Flores Rios, I have some initial questions on the Isolani (or isolated queen pawn). 
The author shows this diagram:


Later, he proceeds to giving White and Black plans for the game. Here my questions arise. 

White is supposed to start a kingside attack. 
I can see no reason why one would do that. I mean White does not have a majority of pawns in the kingside. I would not clearly start doing anything on the queenside but I am not sure why I should do it in the kingside.

Furthermore, if the reason for why this kingside attack is justified does not lie in the pawn majority, I cannot see why the pawn distribution would allow White pieces to be arranged so as to threaten the kingside. White can place a knight on e5 but he can also put it on c5 so it is unclear to me.

I have this very same question also regarding the following pawn structure:


Later, the author suggests placing the Queen and a bishop forming an attack on the b1-h7 diagonal as well as a bishop on g5. These are reasons to start an attack to the kingside but again I am not sure why the pawn structure would suggest doing this.

My second question is why Black is supposed to benefit from the exchange of White light-coloured bishop. I can see this bishop supports the d4-d5 rupture but it seems somewhat exaggerated to exchange it simply for that (maybe there is a better reason?).
To answer your first question, in these structures, white has more space and because of that, he can put his pieces in more advanced positions. Black's king is usually on the kingside in these positions which makes the e5 square a great square for a knight. If the knight was on c5, then black could play b6 and kick the knight out. When the knight lands on e5, f6 would be unwise by black because it greatly weakens the e6 square. Basically, these pawn structures result in more space which means it is easier to maneuver and therefore, start an attack. Also, these pawns are a short term advantage, and without quick action, black could quickly arrange his pieces to attack your d4 (and c4) pawn(s).

Black would benefit with an exchange of light squared bishops because of the fact that the e6 pawn blocks the activity of black's light squared bishop. White's bishop is very strong on the b1-h7 diagonal, therefore, in a majority of circumstances, it is favorable for black to exchange light-squared bishops.