An interesting question, "why wouldn't anyone wish to try?"...
I think the human race has an endemic habit of escaping reality, through use of mind altering substances and fiction, in all countries in all times. In current developed countries, drug use is, perhaps, on the decrease, even commonly legalised drugs such as nicotine and alcohol are taking a battering from political institutions around the world. The alternate reality of choice is becoming digital entertainment...
Why do we do it? My best guess would be our mental capability for abstraction, coupled with mental curiosity and reward stimuli. I think most forms of alternate reality have some addictive element to them because they induce a mental reward, a high, that is otherwise rare or unavailable within "regular" reality.
Escape tends to be generally accepted, in some cultures in history revered, sometimes looked down upon, especially when done in excess (ie. addiction).
Does the conception of this mission explain the nature of the human mind? What purpose is served by assessing the behavior?
Not quite sure what you mean here, patchouli! I think in general people view the desire to escape reality as a more "animalistic" aspect of the human mind and something that should be controlled by the consciousness. As such, I don't think this field is strongly linked to explanation of the mind in general (eg. like in AGI, artificial general intelligence).