Consider that the blade that slices more efficiently requires less force to make that slice which requires less overall strength...think about a simple razor blade, you could snap it in half with your bare hands but it will out slice any pocket knife you own. Of course, lateral strength is almost completely compromised, so you have to find a nice balance between thinness and the amount of strength needed for a particular tool. Compare a Caly 3 FFG blade to a Techno FFG blade. Both are flat grinds, but the Caly has a thinner blade stock and distal taper, while the Techno has 4.5 (as far as I know the thickest stock of any current folder in the catalog) and no distal taper. Obviously one is going to slice better and one is going to be stronger, but the grinds are both "full flat grinds".
If I had a knife designed strictly for cutting rope all day, I would go with a hollow grind in a heartbeat, since the material being cut isn't taller/deeper than the blade/grind. If I had a knife designed for cutting cardboard all day (assuming I'm not just using a simple razor box knife), then I'd want a thin FFG that's as thin behind the edge as I could get it. If I had a knife designed for all out hard use, I would probably go with either a high flat grind or saber grind tanto, something like my Wildsteer WX. This way I have a stout/thick spine, tons of meat behind the edge, and it won't wedge as badly as a hollow grind. Of course, it may not cut rope as easily since it won't be as thin behind the edge as a hollow, but we're talking about maximizing strength, not slicing ability. When you push the attributes to the far ends of the spectrum, you're going to have to compromise something somewhere.