So they give their experiences with many, many students that they've taught over the years, and you say it's not true because you're different?
My example was anecdotal, however when combined with my (Also anecdotal) experiences concerning the education system, the second-hand experiences I noted, and the writings of Russell, Whitehead, Lockheart, and numerous others who also have expounded on the problems with overly structured teaching and similar methods, it provides me with enough evidence to convince me until equal evidence is provided to the contrary.
That is why I say it is not true -- or more accurately, that in my experience, it is not true. I accept that a structured environment is a requirement for some people to learn, but I dispute that it is a hard requirement, and I also dispute that it is natural for the general population to require structure to learn.
Take your average child away from that after several years of being part of it and any short term observations are going to make you think structure is critical. Before they do anything else they're going to have to learn that they don't need structure to learn and after that they're going to have to learn how to teach and push themselves.
First off, that's a circular argument. But also note that research into education is riddled with issues (such as the researchers having moral issues with blind control groups, which results in basically useless data). Our education system is based on the gut instinct of certain administrators. People who clearly would prefer a structured system where one-size-fits-all. Not that I'm saying everyone learns differently (learning styles are also mostly bullshit), I'm saying that the current system could be much better and people who do well in the current system are very motivated to do well and will gladly push with all of their force through the bullshit so they can get on with their lives.
That said there certainly are people that need structure to learn (particularly what they don't want to learn). There are several disorders or disabilities that would make unstructured learning incredibly difficult or impossible.