The biggest rule of interface design is : the user don't care about manual.
That's the user's problem. If the user can't be bothered to read the manual or tutorials to learn how to use a program, I can't really see how that particular user would do better using any other software, in the long run. And especially with 3D software, that is true.
Sure, there are lots of things that could be improved - nothing is perfect -, but if you aren't willing to read a manual to one of the most complex software types out there, well, good luck doing anything nicer than a box in it...
To extend my point of view, I unfortunately feel that 95% of open-source free softwares have the worst interfaces ever, the less intuitive ones. Probably because people developing such softwares are into the open-source ideology, running Linux or other free OS. People who know how read a manual. People who even know how to use a console and more than that, who know how to code ! That's great, but a such community forget one important thing : the "I don't want to waste one week on learning how to extrude along a path" users. (Of course I didn't take one week to do that, just one hour after searching on google). With XSI, without reading any manual, without knowing a fucking thing about this software, you extrude a beautiful shape along a path in 2 minutes. One more minute is enough to make branches to the new-made mesh with other curves etc.
Oh come on. That's incredibly naive. The fact that something is free makes it bad? That, my friend, are the words of an ignorant fool. Not that you are one though, because you prefer non-free software, right?
Or, maybe I got you wrong here. Maybe, what you're saying is that blender should be for dumb people? I honestly don't see what else you would mean with your statement.
What I want to say is I'm sure Blender can do what the other can do. But you lose 95% of your potential users only because Blender interface is... well I'm sorry to say that... Blender interface is shit.
Blender's interface is hard to learn, yes. Once you've grasped the idea and learned the necessary hotkeys, you will use it easily - and fast! 3D Studio Max's interface is easy to learn, that's true. But the speed at which you do things almost decrease by time in it. It's as unefficient as a program can be. Shortcuts ARE faster, and if you're willing to learn them (which you will if you are doing anything remotely serious), you won't have a problem with it. At least not for me, or anyone I've introduced Blender to...
There are, however, lots of things to improve - as I said.