1. Absolutely true. I'm not a big fan of the old school out and back loop. Royal Aberdeen and North Berwick-West also share this weakness. I hate playing 3+ consecutive holes with the same wind trajectory.
"Weakness"?
Some of my favorite courses have out and back routings - Pebble Beach, Cypress Point, Valley Club of Montecito, National Golf Links, Pacific Dunes - and that's just on this side of the pond! The more modern double loop routing is great when it works out, but sometimes out and back works better. I certainly wouldn't call it a weakness.
JMHO of course.
I don't know the Valley Club well enough, NGLA doubles in on itself a bit, the others you mention certainly don't qualify as out and back loops nor does Lundin Links. But Lundin Links does have almost all of its holes running parallel to the shore, as do the "out and back" routings I mentioned. Don't get me wrong. Those courses are spectacular. But they aren't perfect by my personal rubric for the reasons I stated.
I define a double loop course as two separate loops where #1 and #10 tee off at the clubhouse and #9 and #18 greens are near the clubhouse. Please tell me how any of the courses I listed meet those criteria. VC, NGLA, Pebble, the 9th is as far from the clubhouse as you get. The others, 10th tee and 9th green are nowhere near the clubhouse. This is not complicated stuff!
But the point is, an out and back routing, or other non double loop routing, is not a weakness - unless you run out of balls during the front nine!
The weakness I am targeting is having too many holes running in the same direction. I don't care if the routing takes one back to the club house. Pebble Beach, for example, has many holes (3,6,7,8, 11,14,16,17) that do not run parallel to the predominant shore line whereas one could play 9 of the last 11 holes into a headwind on The Old Course. Would I change TOC's routing? Lord no!!! But it is a drawback.