WHOIS Privacy on the website wasn't a consideration on the table the company used. Maybe it's not important in 2018, or is enabled by default, or an oversight, or they're using the spam filtering. But:
Using WhoisGuard for their domain is so not a problem. Namecheap gives you that for free and by default, and it cuts down on spam mail from other registrars.
Bitwarden is open source and self-hosted. This is a better trust model than any of the other offerings by a mile.