Personally, I think it's strange to pay someone so that you can have a second job.
It's not strange, it's a very human, if stupid thing to do.
(But hardly the only stupid/exploitive business scheme that people fall for)
Everything you need to know about MMO's in a nutshell: http://www.cracked.com/article_18461_5-creepy-ways-video-games-are-trying-to-get-you-addicted.html
When you consider MMOs you need to be aware that mechanics wise these games (i.e. refering to Everquest and all its clones including WoW and TOR) have much more in common with gambling than with what is usually understood as "gaming" in the rest of the (non MMO) computer game industry. I.e. they tend to be played for the "joy of getting (virtual) rewards", rather than the (in those games usually rather simplistic and repetitive) gameplay experience.
Yes MMOs work... but they work by exploiting the player. I.e. nothing else but applied behaviorism/conditioning in order to make money... and frankly, I find it kind of disgusting to her people infer that "because these games sell" the companies behind them were "doing something right".
You could as well cheer on the gambling or tabacco industry in my eyes - except at least those guys aren't allowed to sell their crap to minors anymore.
Also: The old Everquest parody on http://progressquest.com/
is still as valid today when looking at WoW or TOR than it was during the time Everquest was popular, because at the core these games are really pretty much all the same: Persistant stat building/acquiring items, to give you the illusion of neverending progress and achievement. That's what gets people hooked and that's why anyone keeps playing them past a certain point despite the blatant repetitive design that those games force on you. (... which is what is supposed to keep you paying and playing.... i.e. "busy" so you never reach the end of "progress" and ask "WTF am i doing here collecting 50 orc noses by killing the same orcs over and over by the pressing the same simplistic 3 button sequence over and over and over.!?!?!?!".)