It seems to me in the first example shown, the play at 1 is worse than "gains nothing"; it is aji keshi since if W leaves it unplayed it can serve as a fairly large ko threat later. In fact there are two ko threats since playing inside the group with four spaces gives another.

At my level (8k or so) I no doubt make many blunders, aji keshi among them and mis-handling ko fights near the top of the list. However, it would not even occur to me to play 1 except as a ko threat or very late in the endgame when there is nothing better left.

Am I missing something? Should the explanation be clarified? Pashley