I can agree a little bit with Matt Cohn's comments regarding the similarity in strategy if you miss the green. I did find in my time playing there that I spent a good bit of time putting or chipping with mid irons, but that's because I happen to be good at that. Look at it another way and tell me if you miss any green surrounded by rough, what options do you have? None...SW it is. Sure, missing RC's 2nd green short, most would pull a putter, but is there anything preventing you from hitting a spinning SW back to the hole? No.
So, while I see your critique's origins, the conclusion you reach is false. You are saying you are left with no options other than putting...when that could not be farther from the truth.
Regarding the Par 5s as a weakness, you have got to be joking. I do not believe there is a finer set of par 5s at any golf course in Southern California, and while I have not played enough golf to really compare at a deep level, I cannot think of a course that has better par 5s out of the great courses I have played....on the west coast alone CPC, Riviera, LACC, 3 Bandon courses, none of them have the strategic interest of Rustic when talking about the Par 5s alone.
As for the same direction, first consider the site, and please explain how you'd propose to better route the par 5s. This, alone doesn't mean the routing is GOOD, but we must tip our cap to reality as well. Saying that all of these 550 yard holes are oriented up/down canyon is akin to critiquing the 8th hole because it's not alongside an ocean. There's simply no other way to do it, and let's look a little closer.
Up canyon is a general direction, but it's by no means "the same" when comparing say, the 9th hole to the 13th. Check out an aerial. You might think it's the same, but there is a solid 40 degrees in differential between the direction they face - the 9th being Northwest and the 13th being North/Northeast. So, we can discuss your criticism in the general sense (up-canyon) but in the actual sense, especially on a course so affected by wind, they play differently.
Even ignoring the routing element of your critique, considering each hole in a vacuum, they are consistently excellent, with the exception of the 9th. The green complexes are all entirely different, as are the tee shots. I'll ignore the first, because we can surely agree that one is in no way similar to any others.
The 5th tee plays games with you regarding angles and blindness off the tee, and tries to tilt you toward the tree/hazard left
The 9th is agreed as a rather boring tee shot, but the green may make you think more with a SW in your hand than any other of the par 5s.
The 10th, with the new bunkering, is a diagonal hazard that a long hitter can reach, and the more you go right, the longer you can hit it, but beware the cleverly placed bathtub bunker. There is no way to reach the green without challenging the right side.
The 13th is, well, one of my favorite golf holes on the planet, so there is no mileage here in talking about this as a weak link. The tee shot is perfect, the green is perfect. It is the best hole on the course.
The lengths may be similar, but they certainly do not play alike. If there is one course in CA where the yardages do not matter, it's Rustic Canyon. I honestly could not tell you what the yardage for any of the non par 3s is there. I just know that at 6:15am the 2nd hole is a 3w plus a 6-9 iron, depending on the wind. One might guess the hole was somewhere around 410-420 yards based on this....imagine my surprise when I saw a number much higher than that on the scorecard.
The 2nd and 11th holes are of approximately the same length. Would you offer the same criticism between these two? Same goes for 14, 16, and 18. All 5 of these par 4s are within something like 25 yards of one another. Is that a problem?
I do not believe the course is above criticism, by any means. The 7th green is a joke, the 15th can get out of hand in dry windy conditions and the tee box does unfairly set the golfer up back toward the 14th fairway, but the two elements you've chosen are the wrong ones to pick on. I would happily play all 5 of those par 5s if they were consecutive holes...screw the routing, they are damn good golf holes, and any out/back configuration is going to have a good number of them oriented in the same GENERAL direction.