As someone who's heard the name "moot", I would have (prior to reading this article, which shows otherwise) assumed that a service named "moot.it" offering discussion forums is associated with Moot/Chris Poole.

Preventing this kind of confusion is the entire point of Trademark law, and whether the company's name did this intentionally or not, I think Moot has a reasonable cause for concern and case.

Trade mark law seeks to balance the interests of people with distinctive brands to protect against the interests of the wider public in being able to use words in a descriptive sense to describe their product.

I personally think moot is very much descriptive of the 'discussion' in general. Moot, the 4chan creator would most probably argue the name has acquired distinctiveness through usage but this generally requires a high evidential threshold in terms of the reasonable person having familiarity with the term as a unique identifier. Whilst if 4chan had been called moot from the start he would have had a stronger case, I do not think the reasonable internet user would be aware of moot's name let alone identify it with online discussion.

moot doesn't have a trademark on "moot", and "moot" does not appear anywhere in the 4chan branding. It's a guy's nickname on a forum.

They have "respectfully suggested" because there is no infringing use to sue over yet, and they likely prefer that the startup change it's name to a drawn out legal battle - it's better for both parties.

There is quite a strong case I think. Moot is the online brand of a person who runs one of the most popular forums on the internet. Starting a forum service with his name is quite clearly in a grey area if not outright infringement.

Sending a letter without outlining your legal position is precisely the kind of approach which could lead to a drawn out legal battle. Outlining your legal position in terms of agreed law will help to remove ambiguity and opinion from the equation and help the other side to better assess the merits of the case. In my opinion this hasn't been done because case law is not on moot's side.

However the main reason why there will be not be a long drawn out battle is because there are likely to be no damages and moot.it are unlikely to have any real assets.