Originally Posted by lionx
One of the reasons is that, people all already go there. Its easier to form parties when there are a common interest in leveling spot.
Also there might be a lack of knowledge that Buburimu is much easier to level in since Mandragoras are like pansies compared to the power of Lizards. (lvling in valkurm from 10-13 is SUCH a pain). Or maybe leveling of exotic mobs are something they dont know much about since they never fought them before and trusting one person that can waste their time doesnt make it worthwhile to them.
Some people are also unlikely to change spots because they listen to only what people tell them. That and also the fact that some people never know where to level and can waste tremendous time. Like for example if you try to level in places alternate to Altepa and Garbage s-h-i-tadle, you can level on Ironshells(or was it steel? @_@) near Norg entrance. However since its so far away the turnover rate is high.
Say for example if you form a party in Jeuno where like 85% of the parties are formed (which will take up to 5-1hour+ depending on availibilty of jobs), you have to wait for a max of 20-ish minutes to get from Jeuno to Kazham and that does not factor in the problem that should there be some nub that misses the airship(which will waste at least DOUBLE that time). Then you navigate through the jungles to get to Sea Serpents Grotto. While this place is MUCH better than the other leveling areas if some person decides to disband early where are you going to find a replacement? They might never been to Norg or they dont have a map and its just pain to get to, and hence your party disbands. Same with lvl 60 partise in Valley of Sorrows or Cape Terrigan. Its so annoying to get to these areas, that usually a replacement or whatever is not going to be found because of the hardness to get to certain areas. Because by the time they get there, 20-40 minutes would have passed depending on many different factors.
So yes alternate areas are great, but these are some reasons i can think offhand are why some people dont level in different areas. Some are not unjustified, some however are just plain silly.