A lot of professional historians don't like any popular history, although I think there is a lot of nuance within that category. What you're talking about is the dregs of pop history. The books usually function by positioning themselves as "knowing a secret" that the historical establishment doesn't want to know. They can throw out lots of facts that sound plausible, but the ideas are so far out there no professional historian would consider the theory. People eat up the theory because they don't have enough knowledge to debunk the claims themselves, and knowing a secret makes them feel special.

The problem with this is that legitimate historical books get ignored in favor of these conspiracy theories. Unfortunately, the historical establishment also tends to discourage it's members from writing books for a popular audience, which leaves a gap that these kinds of books can take advantage of.

Sensationalist history literature might be useful to engage people in History who might not be interested otherwise, but that's about it. The problem is that historical "literature" written by people who can be described as self-publicists and who are proven liars, like Bill O'Reilly, are most unlikely to be any kind of accurate objective history, and are far more likely either to be polemics and distortions that support their particular viewpoint, or are likely to try to deliberately create a sensation. In any case, they are unlikely to be original research or works of any level of scholarship worth reading.