The problem isn't level cap per say, but rather the speed at which you level up.
Level 1 and 2 should go by fast, these are the training wheel levels, but after that you should be at your level for quite some time. I find it odd that you can on release reach level 5 during Act 1.
I find it odd because Level 10 is the announced max level, and there's supposedly 2 more acts?
But, I do like getting to level 5 fast, because that's when the magic happens for most classes. Which is why I think they have set the cap at 4 in EA.