I can agree with this, as it can get you open to seeing ideas that you hadn't previously thought of that are honestly good ideas. It can also let you fight a larger variety of opponents besides the ones that are simply in your local area as well, which can mean you can see far more diversity amongst similar characters and the like. And even with certain things such as spacing/timing being off, you can still see things like say Marth's Fsmash and see which distances are about right (I'm still off because I'm so used to Melee Marth). So even with Wi-Fi's problems, it can at least let you be creative with some ideas. Good connection or not, and unlike training mode, the target actually can fight back.
However, it can also start a lot of cruddy habits as well. For instance, I see far too many Fox's the have come to the conclusion that Dair -> Usmash is unblockable because it works so well on Wi-Fi. I've seen too many DKs that take advantage of lag from the steam coming out of him when he charges a punch. I've seen far too many Ness' try to spam PK Fire like it's the best projectile, so I know it can start as many bad habits as good ones. Not to mention that Wi-Fi often rewards people with poor reflexes, and punishes you for going off of sound cues or frame counting, most noticeably when the lag is inconsistent. If it were consistent with its framerates, I'm pretty sure less people would complain about it.
Honestly, it's quite double-edged. I suppose the topic title isn't incorrect in saying that it is "one of the best ways," but certainly not a way that works for everyone. I like it for thinking of ideas and wondering if they actually work. If I feel like I'm just playing with a lagmaster or the connection is too bad, I don't like it, win or lose.
