YC doesn't run your company for you, but a big point of YC is that they provide advice and guidance. As they say in an article [1] linked from the YC FAQ:

   Most people don’t do YC for the financial investment—they
   do it because they want the advice, the help of the
   network, the benefits of the program.

Heck, for a long time YC only invested something like $20k and got something like 7% of your company. From a money point of view, only a complete idiot would have taken that deal. What made it worthwhile was getting access to the YC people for advice.

Now YC gives $120k for 7%, so it is no longer completely idiotic from a purely monetary point of view, but even at $120k most of the value is in the access it gives you to the YC staff and the other people YC puts you in contact with.

Because of this a lot of people have higher expectations for YC companies.

[1] http://blog.ycombinator.com/the-new-deal

Yes, but I had the same thought; along the lines of "does YC really have to do a dinner where someone comes in and tell the batch's founders not to try to make examples of customers/users that are annoying them, because they will look ridiculous at best and, as in cases like this, actively malignant at worst"? Is that really a lesson YC needs to teach?

I really did not wanted to blame YC. My mention of them is mostly because they are the biggest incubator, so people who get in should have at least minimum amount of marketing skills. They literally make fool of themselves in front of their main "customers" and apparantly we are still talking about one of the cofounders. You are trying to run companies worth millions and do such stupid mistakes, it is just beyond understanding for me.