It is commonly understood that hams are stingy. Cobbling a station together from odds and ends is a noble endeavor. However, a good scrounger also knows that in exchange for spending less money, he may have to exert a little more effort or spend a little more time. The integral of effort over time is equal to money (most folks would let effort = 1; that is, time = money). Therefore, money is conserved and all is well in the world. Generally speaking, we hams are aware of this conservation law.
But, there remains in each of us, hams and non-hams alike, the hope that someday we'll get something for nothing. Hamfest raffles exploit this expectation. I'm not really interested in social commentary on hamfests, though. The big problem arises when we lay this expectation of something for nothing before the laws of physics.
This would be a good time to pause and introduce the three elements of this essay: science, engineering, and art. The role of science is to explore and explain the way things are. Engineering is the application of science to solve a problem or obtain a result of some value. Art is the application of experience to solve a problem or obtain a result of value. A good engineer is both an artist and an engineer. Life experience alone definitely makes you an artist, will help you become an engineer, and won't do you squat for becoming a scientist. Science, engineering, and art, are all of approximately equal importance. However, there is real danger when they are confused, or worse, transposed.
The problem I just cited about expecting something for nothing from the laws of physics usually results when someone who is an primarily an artist makes an engineering (or even scientific) claim. I'm specifically talking about antennas, although this is true of nearly all aspects of station construction. Just like hams are cheap, every ham has an opinion on which antenna is the best.
I want to stress again that art and engineering are both valid and valuable approaches to station building. However, they should not be equated. Furthermore, if a decision is not traceable through engineering, it means that it is an opinion, no better than the experience of the decision-maker.
A significant number of hams who own towers, especially Rohn 25G, overload them with antennas. The fact that 150 feet of Rohn 25 with 3-over-3 full-size 40-meter yagis has stood for 10 years tells you absolutely nothing about engineering. The builder's experience is that it is "strong enough." Structural calculations that show that the installation is superior to the recommendations of the manufacturer would constitute engineering.
Without extensive study and training, antennas are generally difficult to understand from a science viewpoint. Very few radio amateurs are qualified to make electrical engineering decisions about antennas, especially those that depart too far from the half-wavelength dipole in free space. Professional engineers have devoted their lives to developing and documenting modeling software for antennas. Most of that software has well-documented limitations, especially in the calculation of losses. For this reason, the models almost invariably out-perform the real antenna. If you build an antenna that out-performs the model, especially by a significant margin, you probably didn't set the model up correctly.
Without belaboring it further, the point is that hams should be free to tinker and opine. In fact, much of ham radio is art. However, be aware that it is nearly impossible to make unbiased, objective decisions about station design without engineering. Engineering is not just numbers; it is a decision process. If you want the most possible performance out of your station, you cannot expect something for nothing. Period. If "it works for me" is good enough for you, that's fine. Just do not make claims about science or engineering without doing any science or engineering.