Your right...a strict comparison between HS ball and travel/showcase ball is unfair. Equally unfair is it to say that HS kids don't want to work on defense. At least that hasn't been the experience I have had with HS ballplayers in my area. Sure pitching and hitting are more glamorous, but I have no trouble getting my kids to work on taking groundballs/flyballs/doing DP drills/defensive drillwork.
My point about the summer was that it is much easier to play good individual defense and team defense when:
A--the playing conditions are better and more consistent, and
B--ballplayers have had some time to get some defensive work under their belts.
Let's face it, drillwork inside is great, and it is helpful, but working on D inside or in a lesson situation is extremely different than taking actual groundballs or flyballs on a field. And, doing proper team D inside is extremely difficult at best.
I think it is a bit harsh to condemn defense (especially team D) in April. It takes time to develop.
If we really want to jump on a soap box, let's talk about the deplorable state of individual and team baserunning in HS level games. It is attrocious. And that statement can be made whether watching a HS game, a shocase tournament, or a travel tournament. Spring, summer, or fall...it usually remains pretty ugly.