There are too many variables to say that avgs dont mean anything. I think that we are looking at one end of the spectrum; the house hack who avgs 230, who sprays the ball all over the place, inconsistent spare shooter, and has mud feet. However, there are bowlers out there who equal their sport avg to their THS or surpass it. With that said. The major key is spare shooting and shot repetition; i believe that is where you see the difference in skill. That is the design of a sport pattern. THS masks inconsistency and missed spares by giving bowlers the ability to miss spares and recover with a string. Or, spray the ball across the lane and get the ball to recover or hold to the pocket.
With today's game becoming more complex and the balls technology at an all time high, it's easier, i believe, to be inconsistent and score at will on THS. So i do agree there to some degree that in this case, the only way averages matter is with handicap. (I'm not going to get into my belief on handicap, We'd be here all night) Unless you bowl in mulitple leagues and in multiple houses.
As stated above, avgs will matter with correlating THS to Sport Patterns. It shows inconsistency in spare shooting, accuracy, making transitions, and ability to repeat shots. Some guys are good enough to make sport patterns look like THS. Is that a far cry with the strength of balls and the rev rates being higher than ever. We know that some houses are not equipped to layout sport patterns the way they are designed to look to the bowlers, but I think its a bit unfair to criticize a house for putting out a "THS" when you throw a strong asym with a strong layout and 500 rpms. The Scorpion Pattern in one house is going to be different than the same pattern in another house even though they can be the same pattern with the same units. There are many variables that play into that. As far as the bowler, we see it with bowlers on tour. They know what the shot is and make adjustments from the breakdown of the house. They know what to look for so its easier to be consistent and they have ability to repeat shots. Avgs give bowlers who do a multititde of bowling on a variety of patterns, the ability to see strengths and weaknesses in their game and make adjustments.