I meant it was a convenient out-of-the-way place for the heroes to land and plot the rescue, Obi-Wan picked the place because it was out of the way, landing in Mos Eisley or somewhere similar is bound to attract attention.
Obi-Wan is essentially a wizard in the OT, it connects with that mythic side of Star Wars to have Ben's ghost appear strongest in places of power. He is only a voice after his death in ANH, he is a pale ghost on Hoth, he barely appears on Dagobah in ESB but in ROTJ he has a full on exposition scene where he sits down and finishes the story he began in his home in ANH.
It's a place where Ben has a connection and a place Luke will associate strongly with Ben.
The stongest case for setting it there however is the story.
The only way to get Yoda's death to work is to start Luke's journey on Dagobah but to have such a long expositional passage without a break creates a drag in the beginning of the film.
Moving Ben's half of the story creates a new level to the rescue.
In the theatrical cut it looks like Luke has put all his eggs into one basket and it's impossible to imagine what would have happened if things had gone differently.
Having Leia impatiently rushing in to save Han takes some of the responsiblity of them all being in that mess off Luke and makes Leia more believable as being from the same stock as Anakin in ROTS and Luke in ESB.
His expostition begins to serve a purpose within the story instead of just a cop out for the writers who had painted themselves into a corner.