Here's why I don't think decentralization is a red herring: in a centralized service, if you disagree, you don't have another option. If you didn't like AOL and quit, there was no way for you to maintain contact with AOL users unless both parties used a different platform.

Decentralized systems like phone, e-mail, and mail allow you to maintain contact with people while having control over your provider. I understand that we've lost some of that control, but the basic idea stands.

If you don't have Facebook, you can't reach out to other Facebook users. If you don't have Verizon phone service, you can still call Verizon users with AT&T or <insert your another phone service>. If you don't have Gmail, you can still send e-mails to Gmail users from Yahoo or <insert e-mail service>. If you don't like USPS, you can send mail through UPS or <insert another service>.