Gom, the idea that people who find value in a statistic are guilty of believing everything they read is ignorant and a blatant, self-serving strawman. If you'd ever get over your intellectual laziness and read the explanations given by the people who create these new stats and their acknowledgments of where they are weak, you might be able to find value in them too. For instance, most of these guys who have created defensive stats will tell the reader that even a full season's worth of data is usually not enough to give an accurate depiction of the player's talent, which is why you see so much variation from year to year. Does that make it invalid? No, it just means that when you are looking at one season's worth of information, you need to temper your expectations. It's very likely that defensive performance is prone to large variation and that a single season will never provide enough data for a clear view, which would make the stat acceptable provided the user kept the limitations in mind.
Gom, you aren't guilty of an instance where you believed "everything" you've read. Nobody is. If people believed everything they've read, they'd truly believe in nothing because there's something out there on both sides of every issue. However, you are guilty of deriding some for believing "something" they've read (stats), yet you are also guilty of believing "something" else, such as a transaction rumor or an editorial piece. This is hypocrisy. If you are going to soapbox against using information from outside sources, then you need to stand on an island and use only the information inside your own head. I suggest you refrain from this, because the library seems empty.