So if landing one of these candles isn't an objective, why are they trying to do it?
It's an objective, but not a primary objective.
Primary objective is to put the satellite in the planned orbit. They accomplished this.
Secondary objective is to recover the rocket via a controlled landing. They did not accomplish this.
A secondary objective is, of course, secondary (to use a tautology). It's something that's nice to have accomplished, but even if it doesn't happen, the event isn't a failure.
If you want a famous analogy, take the mission that killed Osama Bin Laden. Primary objective was probably something like capture/kill Bin Laden. Secondary objectives was to capture others and bring them back for interrogation, as well as to recover documents.
The mission killed Bin Laden. But due to the loss of one of the copters, they weren't able to bring all the captives back. They accomplished their primary objective, but failed to fully carry out their secondary objectives.
Yet few would consider that mission as a failure.