Here are some reasons for the recommendations you see here.......
I went through a few myself before I realized some things I was doing wrong and spent hours watching their behavior. What I learned:
Anenome don't conciously do anything....but more react to the enviroment. Once you realize that the anenomes actions are a direct corelation to its enviroment, the happier you both will be.
Anenome when purchased are usually stressed due to shipping and are not in the best of health usually....they are weak from lack of light and worse dyed to give them a more appealing color......so assuming your tank is optimal, most anenome will be a little on the "sick" side for a little while until established.
As mentioned anemome only react to the enviroment, so if the water quality, flow, or light is not adequate, they will pull up stakes and wander until they find it, unfortunatly they are trapped in you tank. A wandering anenome is not good,(BTAs seem to wander the easiest though), if not happy they will wander and wander feeding off themselves for months and wither away, all the time "appearing" healthy and the owner is perplexed why it died.
Unfortunatly, by the time the owner notices the signs of an anenome starving, ie bleaching or withering away its on the fast downhill slide....at that point it is too weak to fight off an infection or heal a tear and dies.
Probably the most IMPORTANT and NEEDED thing to consider is lighting. Intense lighting. I was very stubborn when I first got into anenome and killed my fair share....because I didn't have enough light.....Metal Halides are intense enough to keep anenome long term, and would not suggest keeping one in any less than that. Sure, intense PCs and obviously T5s would work, but you will rely on supplemental feeding more and increase the odds its not getting its needed daily requirments. And yes, I have heard of the guys who had 10 BTAs that split umpteen times under N.O. lighting and never were fed........but remember that these suckers live for decades in the wild and five years is considered a "success" in the hobby, and stories are just that...stories.
I have always thought the tone of this article was spot on:
http://www.wetwebmedia.com/marine/inverts/cnidaria/anthozoa/bubbletipanemones.htm
another
http://www.wetwebmedia.com/marine/inverts/cnidaria/anthozoa/anemones.htm
last one I liked:
http://www.wetwebmedia.com/btanemmarcq.htm