Cloudflare's position is that they are neutral and will provide their services to anyone and everyone. They do not make those value judgements deciding who deserves their services or not.
The fact that they thus provide their service to booters isn't a flaw in Cloudflare's argument, in fact it's consistent with their position.
The author is implying that Cloudflare should independantly make that value judgement against a booter, rescind their services from the booter, thus allowing other booters to take that booter down? That's ridiculous. All the booters should be dealt with by some legal authority.
EDIT: So according to some comments cloudflare sometimes does decide independantly to rescind their services from some users? That would make them inconsistent in that case. The authors argument, that the solution to booting is more booting, still doesnt make sense tho imo. It's like the solution to too many guns is more guns.