[speedgoose]

Why do you want them to rely on the company DNS servers?

[jlgaddis]

1. Internal names won't resolve if a client is using, for example, 1.1 as their DNS server (breaking, among other things, logging on to an Active Directory domain!)

2. Many companies have established DNS logging and monitoring in place for security.

[deeter72]

Active Directory, Internal Domains, monitoring, blocking, etc.

[topranks]

Policy.

Not sending my private browsing data/DNS history to a third party (Cloudflare, Google etc.)