Is there a reason for WP:NOTHOWTO?

As much as I like WikiHow (somewhat limited by the fact they don't allow commercial re-use of their crowdsourced content), is there any reason the Foundation should not recommend reversing WP:NOTHOWTWO?

Knowledge can be divided into three types: semantic, episodic, and procedural. Is there any reason that the first two are allowed in to Wikipedia but the third is not? Is claiming that Wikipedia strives to collect the sum total of all human knowledge simply false when excluding procedural information is a policy?

Encyclopedias have traditionally included procedural information. Why should ours be any different? Is there a way to refine the WP:NOTHOWTO policy which would include the most important procedural information (like notability standards)?

Actually, the Foundation does have two projects where how-to information is provided: Wikibooks and Wikiversity, especially the former (although neither are as nearly popular as their Wikipedia sibling or WikiHow). I'm of the opinion that "how-to" information isn't, strictly speaking, a totally encyclopedic topic, and probably is more appropriate to devote a separate wiki for it.