I do not think Nexon will remove the dungeon limit, but they have to realize how bad it is. For three days you dungeon and then you have four days of doing nothing on that character.
Some people may not enjoy an alt they leveled, but are only doing it to have 30 more runs.
So, how about making the dungeon limit account wide. Then let it increase by 30 for every alt you have. So I have three level 50s. That means I can run 90 dungeons on my main character. I do not like one of the classes I have as my alt, but still need to run the 30 for the loot. Having it this way just lets me run the dungeons on my favorite class, while also having put in the time of leveling another character to 50!