Well, I'm not sure if the author is saying that the access period is a bad idea, or that availing oneself of it is a bad idea.
I would certainly agree with the latter. As for the former, we already have a lot of ways for people to throw their money away, so why not one more. Literal actual gambling is legal in many places, perhaps even most, so I don't think I could argue against this form of gambling being available too.
Related to this, I do think the question of what should or shouldn't be legal is a bit of a separate question. Of which this data is only one part. (to be transparent, I'm the author of the post)
I'd rather have the option to enter a market when the odds are against me than not have that option at all.