The game is currently in beta. They're still in the process of porting the heroes while still maintaining the current gameplay; perhaps once they get a good balance they can move beyond the limitations of Warcraft 3's engine and start playing with different ideas, but for now it is what it is: A carbon copy of the original with shinier graphics.
Not to say that it's a bad thing, but it's not like I expected much more for the time being.
Besides, there are countless times that a Scroll of Town Portal (the 135 gold item that emulates a recall, and cannot be interrupted by things other than stuns and silences) has saved my ass with creative fog of war abuse. It does require a slightly different mindset; do I buy the scroll and port in, saving myself a trip to the lane, or do I port back and have to slog through the other creeps, possibly blocking them and pulling my lane back? Or, do I save it for teleport to a lane in need of help, or a pushed back lane that would have fog of war covering a gank approach? Do I even buy it at all, considering that the gold cost may disrupt my buying a necessary item, or will the time saved make up for it in gold and experience? Will I be able to make it out of this 3 man, double damage runed carry coming bottom, or should I run to the side shop, grab a scroll, and haul ass before they managed to kill me? If I have a character with a magic immune ability (Juggernaght, N'aix, or someone with a Black King Bar), will it block their stuns barring them using an ultimate? These examples are the ones I can think of without having played DotA 2 for a while, and there are far more creative uses for them. Or at least there used to be, with the scrolls granting towers a near invulnerability for the duration of the channel, but that was changed into another mechanic, AKA Fortification.
There's more than one way to use it, which adds to the depth a bit. I do agree that certain mechanics are a bit... clunky, and were streamlined or removed altogether in League, but it's best to think of DotA 2 as a completely different game anyway. I do foresee some mechanics being changed in the distant future, but they have to get to where the current Warcraft 3 version is, and that's going to take a while in itself.