I'm sure they would, if it were actually a "troubling trend". There are hundreds of thousands of people at WDW every week, and a very small percentage of people are as rude as the person observed in this post. If it were more than that, everyone from The Orlando Sentinel to Fox News would be reporting on it.
Rude people just get all the press -- even here on the DIS. No one ever comes back and reports about the 500 instances of people being nice to each other that they witnessed. They talk about the one mean guy yelling at Thunder Mountain.
Disney does back its CMs. But it's also to everyone's benefit to get a difficult situation fixed quickly. Get everyone on their way before it turns into a scene. So what if some difficult person gets to use their FP late? Okay ... so ... they "won". Woo hoo. At some point it will come back and bite them -- it always does. But it serves no one for security to come in and bounce someone from the park for being rude. It's not going to "teach the guy a lesson", and it's not going to stop the next guy. If punishment were a deterrent, putting bad guys in jail would bring an end to crime.
Besides ... there's no standard. Everyone's tolerance level is different. There were times when I was working strollers that people would be frustrated or upset or just a little OCD about how long it was taking to find them the perfect stroller (as they kept trying out new ones because little Mikey didn't like the last one) ... and those guests were difficult. Some CMs I worked with would ask me how I could have possibly stayed calm "during all that abuse". And I would be all ... "Um ... what abuse?" What they perceived as an impossible abusive guest, I perceived as a difficult situation that required patience. There is no standard for when it's bad enough to call security. What one CM thinks is worthy of a call to security, another CM may see as a hot, frustrated father and let it go.