Abuse as correct, frequent use
Perhaps the word is used neutrally, or even entirely positively now, but I think it's pretty clear that its meaning morphed over time from a more typical, negative, use of abuse.
I'm most accustomed to hearing abuse collocated with mechanic, for example, I found a discussion on Reddit with the title "What mechanic do you abuse the most?" The questioner is asking about what tactics players exploit in order to succeed in the game - and although the content of the post doesn't mention anything about unfair exploits, that might reasonably be interpreted from the use of abuse in the title.
Look at the top answer:
Being able to barricade my base off with a layer of cars around it as a wall. They can't do much currently. Hope this gets fixed with animations update.
The poster explains the tactic, but hopes that the game developers will fix the bug, or whatever it is that allows this exploit to work. This is a hope, because although the tactic works, it is seen as unfair.
This looks to me like a very typical use of abuse. The player is abusing some AI weakness - abusing because this is not thought to be fair play; this is not how the game should work.
Here's another example from the same discussion:
The knife mechanic feels very overpowered at times
For whatever reason, this player thinks that the knife mechanic should not be so powerful, and so its use qualifies as an abuse.
However, in the same discussion, we can find other answers that describe tactics totally neutrally:
Sound. I love being able to lay a few traps, use an old alarm clock to call a herd in, and then just let loose. You can clear a good chunk of a town that way, and it's so easy. Set up a trail of alarms that go off 5 minutes apart, starting in the center of town. Make sure you have plenty of time (set them to go off overnight), and place them near buildings and alleys. The herd will slowly wander off down the road and by morning your neighborhood is a lot safer. If you have a single remote noise trap set up near your "driveway" you can avoid becoming beseiged for too long. Taunt zombies to pull the fringe of a herd toward you, allowing you to slowly kill them off.
This answer to the question "what mechanic do you abuse" seems to interpret abuse in the same way as the original quotation. Abuse basically means make effective use of. And it's fairly easy to see how a term originally meaning take advantage of a broken part of the game would transform into take advantage of a broken part of the game.