Not really - the translator should handle it. I don't agree. It's the same principle that you already stated: you're saying that Texinfo should support <partintro> for Docbook, but we're saying that since it's not supported for any other format, that is not, in theory, what we'd like.
In the specific case of <partintro> I'm willing to make an exception since it is easy to do (right, Patrice?) and basically harmless given the warning for other output formats. But that doesn't alter the principle. What if <partintro> goes away in some subsequent docbook revision? In my view, that is docbook's (and docbook users') problem. To restate what I think you already said: - I am not opposed (in theory) to adding features to Texinfo that are useful for all output formats. Like the indexing stuff. That doesn't mean that, in practice, it's going to happen in the foreseeable future. - I am opposed (in principle) to continually tweaking things in Texinfo that only benefit Docbook output. Like the full-on part feature in all its glory. That doesn't mean that, in practice, I'm not amenable to the occasional exception, like <partintro>. k