I believe that school is an important step in the career development of many people. Whether or not school is useful on the other hand would depend on the school and the individual. There are plenty of schools that claim to teach videography, digital filmmaking, television, computer graphics or whatever and are horrible at it. While there are others that teach the subjects very well. There are also many students who attend school for four years or more and don't learn anything useful because they don't apply themselves or resist the educational process.
To me the point of an education is to cut down on the learning curve involved in mastering a new skill and allow you to make mistakes in a safe environment, not to mention that it can be a great opportunity to network with other future professionals. Cutting down on the learning curve is important, it takes time & practice to learn how to shoot, edit, and create effects, etc. sometimes a lot of time and practice. Editing for example isn't just about knowing how to use an NLE, anyone who thinks that isn't a very good editor. Editing is as much about learning/understanding the aesthetics and vocabulary of the visual storytelling process as it is about pushing the right buttons. It isn't about only knowing how to cut but when and why to cut as well. It takes years to develop a solid visual aesthetic, and that time can be improved with the guidance of a knowledgeable/experienced mentor. The same is true for effects, and sound, and cinematography and just about everything else you can think of. These are the kinds of things you can learn at a good school, with good knowledgeable instructors.
In regard to being self taught, or using tutorials or books, there is one draw back that I have seen over and over again. Most books on software, and tutorials as well merely tell you how to do something without explaining why you are doing it, or what other options you may have. This leads to the ability of the student to be able to perform a specific task but have no idea what the logic behind that task is. What I have seen this lead to is massive gaps in the knowledge base of the self taught individual, like the web designer who doesn't know what FTPs are or how to upload a site from DreamWeaver, or an editor who doesn't know what drop-frame timecode is, or how to open their programs audio mixer, or even why to. I am not saying that everyone who is self trained is like this, only that it is a trend i have personally seen over the past decade or so. I believe that tutorials and books are great tools after you already know the fundamentals of a skill or apiece of software. They can really help open your mind and skill-set to new possibilities.
I don't see how spending a ton of money on equipment that you don't know how to use works out in the long run. I mean I suppose it can for some but the amount of trial and error required to become good seems like it negates the money saved on an education. And you will find people in every area who feel that an education is a hindrance but you will also find one who won't even look at a CV if the person doesn't have a degree. It is a personal decision by the person doing the hiring, and I don't think there is any way to predict it. I do believe that your career prospects will be more flexible with the degree than without it.
I am the first to admit that I am biased by the way. I hold a MA in Communication Arts with a specialization in Computer Graphics, and also undergraduate degrees in Art & Design and Education. I have been an educator for more than a decade and used to run a community college level CommArts program. So obviously I am very pro-education.