In a way, yes, some of the less intuitive mechanics have become so deeply ingrained within the game that most longtime DotA players would probably throw a fit if they were removed. Myself included, to be perfectly honest, since I've been playing it since I got Warcraft 3/TFT somewhere around 2004 or so, if not a bit earlier when I'd stay over at a friends house and abuse his computer, since mine wasn't up to the task at the time.
On the other hand, it does add a bit more depth to the game. The randomization, the ability to micro creeps in order to stack multiple camps at the same time (or just skillful microing in general), minor variances that can lead to a large gap in gold, the chance based mechanics that have to be either accounted for, such as firing up hill (a relic from Starcraft days that was intentionally left in DotA) by either itemization or moving to a more tactical position, or even the more basic things such as orb walking via animation cancellation... there is a lot more to learn and master than in most games.
Even something as basic as denying takes twice the amount of concentration than simply taking out enemy creeps, as you have to pay attention to two sets of health bars, as well as any enemy heroes in the lane (and possibly, depending on your team's level of communication, enemy heroes not in their correct lanes)... as well as if the positioning of the creeps are good for farming, or if you should back up, or if you should rice the lane by autoattacking your creeps once they get below 50% health, in order to move your lane back to the tower, or if you are in a position to creep pull (Scourge top lane has a disadvantage here, because you can pull the "hard" camp on the left with a quick tree chop from Sentinel)...
Juking is another field of play entirely. Abusing line of sight, cutting trees in such a way that allows you a quicker exit path (or lures enemies deeper into an inescapable trap), and using the map geometry to your advantage when appropriate (a la Pudge, who can just hook people into places that they won't get out of until they die... which is better if you get a Hatchet, which allows you to create those areas in denser forests)....
Sure, it sets the learning curve higher, but it does make for a much more interesting (meta)game once you start to grasp the basics. Kinda like Dwarf Fortress.
I don't agree with all the limitations of the Warcraft 3 engine they've left in, but I expect they'll start learning and playing within their new engine once they start getting all the heroes added in. Being able to lifesteal on Luna without losing a full 4 point skill was pretty nice. Then again, they may have fixed that between the time I stopped playing the Warcraft 3 version and now. Enough drunken rambling, time for bed.