I can't speak for david_e, but my observations of negative posts fall in four categories:

1. They are objective problems with Kobo devices. These are reproducible, and produce results that are clearly wrong (ranging from crashes/freezes to not fitting the conventions for publications). The importance of these problems will vary from user to user.

2. They are subjective problems with Kobo devices. These are reproducible, and produce results that are not acceptable to certain users. (These are usually the product of design decisions.)

3. They are objective problems, but difficult to reproduce. These are real problems, but they affect a subset of users. This may be due to manufacturing defects or improper use of the device.

4. Support related issues. I don't know what to think about these issues, because a lot of the people who have brought them up seem to be the type of people who would earn poor customer support (i.e. their mannerisms are more confrontational, which may illicit poor support from the business).

I'll add a fifth category for fun:

5. Antagonistic. These are people who are clearly upset. The reasons may be legitimate, but they are unable to separate their emotions from the events and present a highly biased representation of the events. They frequently feel compelled to do so repeatedly.

At the end of the day, the sharing of good and bad experiences is a good thing. However, it is best if those experiences are presented in an objective manner. Sometimes customers do so. Other times, they don't.