The role of the Debian Project Leader doesn't really come with a lot of direct power and control over the project. A DPL has the power to delegate responsibility to others on behalf of the project, approve expenses, and some other administrative minutia. Because of the limited powers of the DPL, some have said that the DPL doesn't yield much influence of the project.
The reality is that the role of a DPL provides a commodity that is both very rare and very valuable these days: attention. When the Debian project leader speaks, it's not only the Debian community at large that listens, but everyone. Everyone from news sources, other distributions, business people and government decision makers pays attention to what Debian does and what it's leader says.
I can understand the desire for a project leader to say “I'm only speaking for myself here as an individual DD...”, but I believe that if you're willing to serve as DPL for a term, you should be able to put your own feelings on the side a bit and just represent the project fully as best as you can.