I have been the recipient of several of these unsolicited e-mail and "manuscripts", and let me tell you that other than providing a good few minutes of laughter, I some time feel rather sorry for these people because, most often, the mistakes or inconsistencies were quite obvious. This despite the fact that many of these "theories" are often rather difficult to decipher because they are written in non-standard terminology. The words being used are familiar, but the context they are used in are rather odd. Certainly, the advice given in that article is very pertinent here:
To merit their attention, professionals say, an outsider would have to show that he’s done his homework. Serious contenders have to understand the language of physics and get their math right. Most importantly, any new theory must agree with past experiments.
A theory could predict that hula hoops will come bouncing out of CERN’s Large Hadron Collider in Switzerland, as long as it accounts for all the experimental data up to that point, Rizzo says. Too often, amateurs ignore that basic constraint.
I would say that the amateurs "ignore" that constraint because they tend to not be aware of all the experimental data, or are ignorant of the body of knowledge in that field of study. This is another example of what I categorize as "imagination without knowledge is ignorance waiting to happen". There's no substitute for doing one's homework, and claiming something that contradicts or inconsistent with existing data or observation without realizing such data exist reflects one's ignorance. No professional scientist wants to be shown to be in ignorance of the state of knowledge of the field he/she is in, but this is what many "amateur physicists" continue to exhibit without shame.