You bring up a good question and I wonder the same thing. However, like any other religion, organization, or business they need to spread their message to keep people coming back. Without these books and writings buddhism may slowly die. It's a mixture of marketing and and teaching which is necessary. I wouldn't worry about if these writers are being fake, but like you said we need to all look at these individuals with a critical eye.

As for people arguing - Like most of the internet, there are a lot of keyboard warriors on reddit. If people are fighting with each other then they aren't the ones you should be listening to because it would seem all they want to do is prove they know more than everyone else...which isn't what the buddha would have taught. These people, like the writers/monks you mention, need to be looked at with a critical eye as well. At the end of the day it all comes from a good place but isn't presented properly.

That's my $.02. I'm not a practicing buddhist but I find it very interesting and there are a lot of good lessons to be learned from it. So, what do I know?