One letter domains has the same issue as many of the gTLDs, they aren't particularly useful in terms of brand recognition. X.com is pretty stupid as well, you can't meaningfully use it as a brand. Take bob.builders, it's a perfectly valid domain, but if you see it on the back of a van, even if it's www.bob.builders, it's not recognizably as a website. www.b.com has the exact same problem, even x.com / www.x.com is ju…
No, I disagree with the idea that one letter domains look wrong. Especially with the many new TLDs, more often than not short URL services use single character domains. Take g.co for example—google uses that in ads everywhere. It’s modern equivalent of calling a short code phone number unrecognizable. But yet most people still instinctively know how to text them for information. However for really esoteric TLDs, I can see why it would be more of a problem, not because the length of the domain, but that the TLD, like .jobs, just doesn’t sound right.