Sometimes this is true, and sometimes it's what CORBA advocates say you to get you to adopt object brokers. Sometimes your app benefits from an explicit networked database tier, and sometimes it doesn't. I'm fine if you think most of the time it does. I'm not fine if you think it rarely does: that's not true. There are big advantages to not having a separate database tier, and the industry is sleeping on them.

(To be clear: the company I work for sells a Postgres service, and we benefit from n-tier databases! I have strong opinions here because I think this is an interesting controversy.)