Are Poomsae designed to fight multiple opponents?

I had this discussion the other day on the internet with a "TKD Master Instructor". He basicly believed that everything in the mainstream texts when it comes to applications are the one and only. All the Poomsae are designed to fight multiple opponents and each time you turn you turn to face a new opponent. I said that yes this is one way to look at it, but for me the opponent is situated in front of me and the turns are to tell me where I should postition myself, to get body weight into grappling techniques, to learn how to develop hip twist as power generation etc. He then quickly pointed out the classic double blocks that are "obviously" designed to block two opponents attacks at the same time. I gave him some realistic applications against a single opponent instead. In the end he said that he would continue with the way he learned allthough I had "clever arguments":-)

I then tried to find out what the founders of Taekwondo said about this issue. I did not really find anything so I thought I should see if I could go nearer to the source so to speak. As forms in Taekwondo came largly into our art because of Japanese influences and because all Kwan had Karate roots looking at what the Karate teachers said about the issue is one way to enlighten ourselves. Then I stumbled upon this excellent piece of writing by none other than Kenwa Mabuni teacher of at least one Kwan founder. I guess that next time anyone wishes to discuss this issue I will just send them this article written by Kenwa Mabuni and translated bu Joe Swift:

"Kobo Kenpo Karatedo Nyumon by Kenwa Mabuni as translated by Joe Swift:

The meaning of the directions in kata (Poomsae) is not well understood, and frequently mistakes are made in the interpretation of kata (Poomsae) movements. In extreme cases, it is sometimes heard that "this kata (Poomsae) moves in 8 directions so it is designed for fighting 8 opponents" or some such nonsense. I would like to specifically address this issue now.
Looking at the enbusen for Pinan Nidan (Pyung Ahn 2 Hyung), one can see that karate kata (Taekwondo Poomsae) move in all directions, forward and back, left and right. When interpreting kata (Poomsae), one must not get too caught up in these directions. For example, do not fall into the trap of thinking that just because a kata (Poomsae) begins to the left that the opponent is always attacking from the left. There are two ways of looking at this:
1 - The (Poomsae) kata is defending against an attack from the left.
2 - Angle to the left against a frontal attack.
At first glance, both of these look alright. However, looking at only number (1), the meaning of the kata becomes narrow, and the kata, which in reality must be applied freely in any situation, becomes awfully meager in its application.
Looking at an actual example, the 5 Pinan kata all start to the left, and then repeat the same series of techniques to the right. Looking at interpretation (1), the opponent must always attack from the left, and while fighting that opponent, another opponent comes from behind so the defender turns to fight that opponent. This type of interpretation is highly unreasonable.
Looking at interpretation number (2) however, the 5 Pinan kata show us that against an attack from the front we can evade either left or right to put ourselves in the most advantageous position to defend ourselves."

Here is a link to the original site where I found this.

I do not think that I could have any hope to explain the turns and angles in forms better than Mabuni did. And Mabuni was also our teachers teacher so to speak, wich gives him a lot of authority on the issue.