It is daunting for pseudo-gamers - for people who want to play only the max level toons to grind epics. They would be full of happiness if leveling was removed altogether. Just imagine this, Blizzard announces "leveling is gone" - and you would see a lot of threads which say "finally, well done, long overdue!"
There are many games which reach far beyond lv. 120. It isn't daunting, it is very alluring - "hey, look, we will have a great adventure
"
If someone thinks that 120 levels is a lot and who hates leveling experience and wants it be destroyed by level-scaling, he should rethink if RPGs is truly his game genre or maybe he is more into 3D Action games. Level scaling removes the core of RPGs - character progression: there are no "ifs" and "buts".
Just imagine, you would have salary 2,000,000$ a month. However all the prices would also increase by 1,000 times, so bread, which costed 2$, costs 2,000$ now. Would you say that you made some progress? You should be totally devoid of any brains in your head to say so. Level scaling follows the exactly same utter bullsh!t pseudo-logic, Level scaling IS crap. It substitutes character progress by some stinky crappy illusion.