The immediate trigger to this particular discussion was the statement in the referenced blog post that projects "should" have a due date. I can understand those who object to a process that forbids self-set deadlines, but I think that the other extreme of requiring a deadline for every project is equally problematic. If it works for an individual, dandy, but I don't agee that it's a general "should."
Re the "if it rolls, it's a Mercedes" argument, I think that I agree with Folke, assuming that I understand him correctly. I've had a similar issue in the past, with what seems to be a rejection of the very idea of definitions.
Definition: Guacamole is "an avocado-based dip or salad." If something does not involve avocados, or look like a dip or salad, then I would say that it's not "guacamole." That doesn't mean that it's not good, it just means that it's not guacamole.
If a person found a particularly squishy/waxy potato, and treated it much like an avocado in creating a dip, then one might quite reasonably call that dip "Potato guacamole." It might be wonderful and delicious. But if it were presented on a menu merely as "guacamole" and ordered and brought to a patron's table, that patron would have every right to complain and send it back. The definition of guacamole gave that patron a shorthand for what he was expecting to receive. That's what definitions are good for--they're shorthand.
So, "doesn't fit the definition" is not the equivalent of "bad" They are two completely different concepts.
I've been doing a lot of reading about Agile programming lately. Agile's core definition, the core principles, are pretty general, though very far-reaching. And people have come up with multiple practices based on those principles--Scrum, Kanban, and so on. These are different definitinos of "Agile." And there's acceptance that the goals of Agile can be achieved in many ways, and that there's a pretty large range of "if it works, do it." There's also a general idea that certain core practices are non-Agile. And people argue, vociferously, about which is which. But I have yet to see anyone argue that it is wrong to even TRY to define what Agile is. There is a clear acceptance that definitions are useful and meaningful. If the Agile community decided that even trying to define Agile was wrong and unseemly, I think that the practice of Agile would slowly fall apart.
I'm not sure if I've ever seen such a strong vibe that defining something is an inherently negative practice, as I've seen from many posters on this forum. In a forum intended for discussion of a topic, I often get a vibe that discussion of that topic is unseemly and inappropriate. I feel that the vibe on the forum these days is very strongly suppressing discussion that even tangentially touches on definition, and that that is suppressing discussion in general.