As a single founder, I don’t agree with that. Once I passed a few hundred signups, I found that people were willing to write in and tell me what they liked and didn’t like about my service. Now, I find myself with a list of things to get done because that’s what my customers want (not to mention what I personally want). Like the author, I “never feel at a loss for ideas (and have more than I know what to do with)”.
Emotional support, however, is hard because it’s not something you can take care of on your own; until you have people validating your work as worthwhile, it can be difficult to believe in yourself.
I think that “two (or more) heads are better than one” for solving issues, whether they be technical or with regard to how an idea should be executed.
Otherwise, nice essay (although I was hoping for a discussion on why single founders use “we” in their text instead of “I”).