We're talking about the idea that, in order to observe, the nature of observation needs to be free of the quality that you are in the act of observing.
I can think of exceptions in my own experience for this statement. Granted, it's tricky to do, but these characteristics are not mutually exclusive. Otherwise how would we use the mind to observe itself? How
would be be able to observe at all if we could not articulate some of the differences that make a difference - no matter if we are trapped within them or not?
Why is being free a prerequisite? The ability to observe, creatively problem solve or to stop or replace a habit that you don't want for whatever reason is a skill. The nature of skills is that these abilities can be learned and sharpened. Granted, it takes practice. Practice is more effective in the context of when and how you would like to use a skill. It takes the capacity to imagine an advantage to go to the trouble of bothering to train the skill.
Now, the next question that begs is: what could be the advantages of surrendering continuous self-referent activity - in that it may even be a pleasurable activity that someone would want to continue?
For me surrendering self-referent activity is a social advantage. I'm able to imagine what someone else might experience and become able to establish rapport and connection with them.
For someone else who is not particularly after personal connection, perhaps this ability might be the ability to act as a channel for art or psychic prediction. The ability to surrender self-reference could mean to the person some sort of livelihood advantage related to the cultivation of a skill.
For instance, if for some reason you thought you might like to surf, it wouldn't do you much good to think that the ocean is out to punish you and how dangerous it is - it's more constructive if you realize that there are factors of balance and skill to uncover that you would need to practice and learn about the nature of what it takes to surf. Of course, you would have never learned to swim because you have to surrender fears generated by self-involvement...unless you have a good teacher.
This implies that there could be an attraction coming from the lack of something - perhaps the ability to turn off repeating nuisances of internal talk that spin someone into depression would be a great advantage? These are the benefits - the payoffs. Different strokes for different folks sorts of things.
I'm sure people could think of more of these - and I'd like to hear 'em.