Should Wikipedia and related wikis allow anonymous IP editing?

Wikipedia and related wikis allow anonymous IP editing. Is it a good thing or rather something to be abandoned?

Pro

 * Allowing anonymous IP addresses to edit creates something like a beneficial soft drug (of editing), which can lure editors to become serious registered editors later.
 * It is unclear whether luring people to spend their time and attention online on wiki without significant act of volition is actually ethical.
 * Disallowing IP editing is likely to somewhat reduce the volume of useful edits.
 * As per W:Wikipedia:IP editors are human too, "You are an IP too", which can be interpreted as saying that registered accounts are also IPs.
 * Untrue. A registered user account is not an IP account, and a person who has a registered user account is a person, not an IP address. (Ontology matters.)
 * Being a human is not an automatic indication of goodness (skill, intent, etc.), and therefore, there does not seem to be any deep significance of the predicate in "IP editors are human too". (Stupid people are human too; undisciplined people are human too; unskilled people are human too; malevolent/ill-wishing people are human too; etc.)

Con

 * Anyone serious about substantially improving the wiki should have enough time and attention on their hands to create an account. While there would be some loss of, say, minor corrections, arguably, the loss is tolerable.
 * Presenting oneself only via an IP creates a burden on the memory and cognition of those who view edits by the person or interact with the person. Put differently, numerical identifiers are not as cognitively friendly as alphanumeric names.
 * Requiring the hurdle of an account registration provides a disincentive for vandals to vandalize, thereby preventing "dirtying" revision histories.
 * Anonymity contributes to poor behavior online. People all too often say things that they would not say in a face-to-face interaction.
 * That may be true, but registered accounts are also de facto anonymous (they are pseudonymous, but that come out as nearly the same).
 * Fair point. However, psychologically, an IP may feel more anonymous than a registered user account.
 * An interesting point. However, the stated hypothesis is an empirical one and requires proper verification. Absent verification, the above is a speculation.
 * Medical MDWiki run by Wiki Project Med Foundation does not allow anonymous IPs: "Editing is restricted to registered and approved individuals". It remains to be seen how well it works for the project.