Neil Williams writes:

The new lintian addition "missing-debian-source-format" is starting to remind me of a pestering nanny.

I use source format 3.0 only where I see a technical benefit and that - so far - is restricted to packages that use a .tar.bz2 upstream and one or two with really tricky patching requirements.

You are missing the point - debian/source/format allows you to make it explicit that the source format is 1.0, if you want to stick with that.