Many marketing documents are written to pitch to the author, not the potential customer. When pitching to yourself:

• You do not have to explain what your solution actually does, you know it already
• You can boil down critical aspects of the pitch in just a few "place holder words". Reading them will trigger your memory to pull up 15 pages of value proposition in a nano second
• You have a lot of different customer segments to worry about, so you dilute the story a bit to appeal to as many different customers there are, emphasising a few extra benefits here and there
• You do not have to explain technical marketing jargon, as an expert you know it all

Think about this.

Image: Hollywood actress Constance Talmadge, head-and-shoulders portrait, facing right, looking into mirror.