While it looks like a no brainer (you only need press one button to optimize. so why not), the consensus between the mysql experts tend to discard the usefulness of optimizing as a way to improve your wordpress performance.
The real question here is not if optimizing is good or bad, but whether you should dedicate in advance time to perform it. And since while the table optimization is done the site should be offline, does the benefits are high enough to justify it.
What the optimization does it to defrag the files used for the table and rebuild the index. defraging might save some space on your harddisk, but will not impact your site’s performance. The index rebuild potentially can improve performance but in practice it rarely does so, especially for the small sites which is probably 99.9% of the stand alone wordpress sites in the world.
For people managing wordpress networks it might be more complicated as the defrag benefits might accumulate to something substantial, but I have a feeling that whatever the benefit will be, the time and effort needed to communicate to your users that their sites will be down will outweigh them.
Maybe this is something that you should do only when you are already performing site maintenance for other reason like version upgrade.