Bob, I definitely agree with your comments about apparent wind.
Going in an orthogonal direction, though, wouldn't you agree the reason many people buy cruising cats necessitates sacrifices that affect performance?
For example, many people like cats because of the shallower draft but that means they don't have enough keel for windward work. Secondly, cats are fastest when they're lightly loaded but the average cruiser puts in so much gear/equipment the hulls have too much drag so the wetted surface area of the too (typically large) hulls is huge.
a. If I refer to a course relative to wind, I always mean true wind. If someone has a point to make where relative wind is particularly relevant (spinnaker set) they should make that point separately. This convention just seems more clear to me. As we all know, a beach cat or fast skiff is as "close hauled" on a reach as many slow boats.
b. As for why many cats are pigs, there are many reasons:
1. Under canvassed. Many charter designs do this since they don't know the crew or the sailing area. They want to make them stupid-proof. While a mono-hull will tell you in simple terms when over canvassed, the obvious symptoms for a multi-hull occur too late.
2. Lotsa of room for junk. If you don't want to stay light, sail a mono-hull. Although I have a tender on davits, you will find many lockers are empty. I don't haul what I don't need. I have a good tool kit and required spares.
3. Poor feel. Cruising cats are more by the numbers ad what you see, than what you feel, particularly when wheel-steered. My boat has very little helm feel or motion/lean feel until the wind hits 12 knots and boats speed over 7 knots. Then it comes alive and is quite pleasant. But even then the feel is very light, which might bother some day sailing and make fast trim and steering tricky. On the other hand, it makes long passages easy. But the point is that feel is less, not absent. An experience cat sailor gets in tune and works the puffs and waves without the need for much feel.
4. Draft and keel. Yup, draft helps. But I don't think it is the major factor. Any sailor that learned on small cats knows that short (or none) keels stall easily and that you must retain the right balance of speed and side load. I think this is a feel that cat sailors must be more aware of than monohull sailors. It is why pinching just a few degrees is fatal... and yet with the right balance I can tack through 90 degrees, though 100 degrees is generally better VMG in chop, for me.
In the prior story, for what it is worth, the up wind leg required at least 2 tacks through a slot; VMG was the thing that mattered. No cheating by footing. Same down wind, since we are all bound to the same marina. Point to point, windward/leeward.