I think of it more of an aesthetic preference. While I use gmail today I don't negatively view people who choose to self host.

Some people are militant about editors, others are "discerning" (snobbish?) about operating systems or ONLY using free software. It takes all types and they help keep the world going.

It's like a high maintenance garden feature. It signals a few things about you: high technical capacity, unusual amounts of free time, unusual priorities.