There are hard limitations to this beyond the matter of players wanting it or not. Primary among those limitations is the fact that character and guild names are not shared across the regional divide, so you can have the same name for things on both sides.
So what if someone wants to transfer but their character name is taken on the other side? Who loses the name? Both characters are about the same age, so how do you make a choice that's fair to both parties? For sake of example, neither wants to give up the name, so "give the option of a free name change" is off the table.
I think everything is solveable, just like how they solved guild-name issues with world merges.
The ideal should be- if a person chooses to transfer regions, he should take into consideration that he might lose his IGN because there's already someone with the same IGN in the other region, and yes, maybe he'll be given a free name change coupon to pick a new one.
Trust me, I have my first name as my IGN in NA, and I'm willing to give that up just so I could play in the region that fits me without any LAG/delays.
Guilds are out of the discussion because they won't move with you to the new region, just as they didn't with the previous world transfers, if moving is important enough for you then you'll remake your guild, we've been there and done that already with Bera transfers.
This is something that people has been thinking about and wanting, I don't see why Nexon shouldn't be considering it.
So we've had NA+EU merge, NA world transfers and now world merges.
When are we going to get an option to transfer regions? from NA to EU and vice versa?
Many of us europeans started playing in NA because it was the default option.
Now, we're way too invested in NA to leave for EU, but the EU servers are way more better for us ping-wise.
I believe many characters will consider transferring their characters if they get the option.
Was a move like this ever been considered by Nexon?