IK constraint: target to bone`s tail and between head and tail as Track do.

Why IK can only target to bone`s head but not the tail or even to somwhere in the middle? I mean the same fashion as Track-to constraint have?

This is very simple and common situation, that requeres ti add 1 child-bone for each bone that track.

BTW there is a lot things, that force animator to use tangled and very complex rigs, that doubles or triples amount of bones and jump between layers. So it is tiny step to keep it simplier for user.