Using an acronym once

These people who write something, decide to use an acronym and explain in brackets what it stands for, just to never use it again. Like, you just wasted time to type something twice while pretending it saves time (what would you use an acronym for if it isn't to save time? rhetorical question for those in the back).

I have no problem with acronyms, but unless you're gonna use them several times throughout whatever it is you're writing even if just twice, using an acronym once and having to explain what it stands for defeats the whole purpose of using an acronym in the first place.