The flagging guidance text for the very low quality (VLQ) flag option says:
This answer has severe formatting or content problems. This answer is unlikely to be salvageable through editing, and might need to be removed.
In other words, flagging a post as VLQ indicates that you think the post is beyond help, and should be deleted.
If you don't think that, don't flag it as VLQ.
There are other actions available:
- Edit the post to be better if you can
- Leave a comment suggesting ways the author or others might be able to improve it
- Vote up or down
- Leave the matter for someone else with stronger convictions, more time, or greater expertise
Remember, flagging a post as VLQ or NAA adds it to the Low Quality Posts review queue, so you're potentially making work for several other people as well. If the community does not complete the review within a reasonable time, or the case is clear-cut, a moderator may also handle the flag.
My general advice is to think carefully before flagging an answer as VLQ, and to carefully consider the other actions you could take instead (including doing nothing).
The particular answer cited in the question does not seem worthy of immediate deletion to me.