Sounds like a good habit, yeah. But the fact that an attribute access in a template (which might be quite far removed from the view code) can kick off a db query is an indication there's something a bit too magical about the design. Often front-end developers without much knowledge of the data model or the SQL schema are writing templates, so this is a bit of a foot-gun.
I've wanted a Django mechanism in the past that says "any SQL query triggered from a template is a hard error" - that way you could at least prevent accidental template edits from adding more SQL load.
