It's simple to understand. There is a lot of ball movement (as with the AFL, not surprisingly - they both suit the Australian sporting psyche).
Not much wrong with the rest of what you said (whether people like it or not, league has a century head start with administration and marketing -- professionally, they should be even farther ahead). But just because the game is simple doesn't necessarily make it easy to understand, and there just isn't as much ball movement claimed.
Simplicity Isn't Always That Easy
For the simplicity, first just take the 40/20 rule and the ball boy fiasco that happened last week. That led to a full week of hand-wringing and trying to figure out how such a thing could happen and how to change the rules to make sure a ball boy doesn't throw a ball in touch to someone who calls for it. The NRL has changes in rules every year and the league press -- particularly radio -- take comments from the public about what should be changed. (Which doesn't mean they thought the public input on the NRC rules was a good idea -- they laughed at that for a week, even though they do the same thing). There are
fewer rules, but that doesn't necessarily mean it's
less complicated; that can lead to situations where they're not sure how and when to apply a rule, and things get bent, like taking a quick tap off any body part except the foot; or James Graham slathering his thighs in Vaseline to make it harder on people tackling him (yuck); or all the problems with wrestling and how can tackle with a chicken wing or an arm bar or lift a leg and how high.
Movement Myth
As for throwing the ball around, I got curious about this last year and had the time, so I watched a Roosters-Warriors game and counted how many passes each team took before they inevitably ran into a wall of opposition. The Roosters took far fewer passes than the Warriors, and averaged 1-2 passes on the first three tackles. Tackle four maybe got 3 passes, and if they found some space, maybe a fourth. They'd get conservative again on tackle five, and then kick. And it's not like they're getting meters on each of those passes -- the majority were short passes, and the receiver hardly ever targeted a hole or tried to get wide. Almost every time, they turned into contact and turned the run into the mini-maul league has when three players shove their torsos against each other and run as hard as they can until someone can wrestle the other guy down. Greco-Roman rugby.
The Warriors threw the ball around a bit more, but not by much. They might get an extra pass on tackle two or three, but only one extra. On tackle four, they attempted to throw it around more and get wider than the Roosters, and a couple times got up past 6 passes. Maybe that's why I like watching them play more than most other league teams -- they created phases and tried to move north-south more than east-west. But just barely.
Why Those Are Problems
The first problem, from a rugby standpoint, is there's no contest for the ball after the tackle, so the game just stalls and restarts once all the defenders back off. It's like hearing gears grind. You don't get that in rugby -- after one pass or eight, as soon as a tackle occurs, an entire different dimension of the game begins, and depending on the quality of the forwards and the back row, that can change the shape of the defense and open space for the offense to attack
if the scrum half can get quick ball. But presumably that's too much game for some?
Another problem from a rugby standpoint is that the claimed simplicity of league leaves them with fewer options for creative play. It's kind of amazing to listen to former NRL players criticize rugby for trying to kick the ball into space behind the defense when there's pressure off the ruck, but praise Shaun Johnson for his creativity because he might kick before something other than the fifth tackle. In rugby, you don't know if the ball might be run, passed or kicked at any phase, which keeps the defense and the crowd guessing. In league you almost always know; someone kicking before tackle five is rare enough, and kicking before tackle four is rooster teeth, almost as rare as the Warrior's contested scrum against Paramata a few weeks back. Again, it just seems like kicking before the fifth is another one of those rugby elements that's too much for some to comprehend.
I have my doubts that rugby's all-too confusing for average people. Like I said before, I'm in the States, and have had no problem introducing rugby to people who've never watched rugby before, and didn't have a problem when it was introduced to me. The only area that might have some complication is the scrum, but explain the objectives, and it's no problem. When I tried showing those same people in the States league (NRL, State of Origin), they found the lack of ball contest made it more two dimensional, less interesting, and a bit dull (more like gridiron). They also noticed the difference in tackling, and how the league attempts at wrestling a runner down instead of just tackling him led to more tackle-breaks than necessary (that drove my wife nuts).
Rugby's only confusing because league media says it's confusing; if that's all that people hear about the sport, then that's what they'll believe. I'm just as confused as to why they league players flop on the ground like landed fish when they're tackled, but I don't see the NRL clearing that one up, nor does it stop me from watching the occasional game (but it does make me embarrassed for them).
They're similar sports with different objectives at the phase level, and those differences create inherent differences in what you're watching for. Watching rugby with league expectations is like watching rugby with basketball expectations, or gridiron expectations -- you're watching for the wrong thing. The same goes for watching league with rugby expectations (or wrestling expectations; if you want to see good wrestling in rugby, watch the Russian national team). But the NRL media's obsession with rugby seems to show more of a focus on what league isn't than an appreciate for what league is.