I once went to an IDEO talk and noticed that all words in the speaker's Powerpoint are capital letters. After the talk, I asked the guy why he made it like that

I once went to an IDEO talk and noticed that all words in the speaker's Powerpoint are capital letters. After the talk, I asked the guy why he made it like that and his answer was that since capital letters make it harder to read, you would force yourself to write concisely on the Powerpoint. He also mentioned that many people inside IDEO follow this rule. Badly made Powerpoint is just useless while 6-page memo might be too time consuming and inconvenient. Capital letter approach could be a good compromise between those two.