CubicsRube
Hero
I think D&D sits on the fence with this one. D&D however DOES have a very specific setting, and I wish it embraced that.Counterpoint: A lot of what you like about the Witcher monster manual is highly setting-specific. Which is good for a game that comes with a specific setting. But D&D is supposed to be setting-agnostic in order to allow DMs to develop their own lore for the monsters. For example, you liked having the typical price for a bounty, but that assumes that monster bounty hunters exist in a setting, which in turn implies a lot about the economy and the attitudes of society in general. Even "monster lore" locks away a lot of options that DMs might want to homebrew.
For D&D purposes, it would make more sense to put most of this stuff into a setting book. I definitely wouldn't say no to having a section in each of the various setting books talking about common monster lore, crafting options, bounty lists, etc., but I'm actually glad it's NOT in the Monster Manual.
Default options are good for me as you don't have to use the default.
And as mentioned many of the things such as typical combat tactics and how many appear (as well as morale! Much missed!) have already existed in earlier versions of D&D.