It is true that people do a lot of things to animals for their own convenience or pleasure or profit. Many of these practices are considered normal or acceptable in some parts of the world but totally unacceptable in others.
Most people would rather not do any actual thinking about the ethical issues, but instead offer halfhearted justifications like "Neutering dogs is okay, therefore venomoiding rattlesnakes is okay." Or, "Importing reptiles causes suffering and death, therefore venomoiding is also okay." Or, "Snakes suffer just by being in captivity, so it doesn't matter what else we do to them to make them suffer more."
That's a cop-out. Every one of these things mentioned is a very different ethical issue with complex factors to weigh, and they deserve to be considered separately. You may well come to the final decision in your own mind that venomoiding is okay, but you should do it after learning all the facts and doing some real and serious thinking about the individual issues.
Spaying a dog or cat is not a do-it-at-home procedure. It is performed only by licensed veterinarians who use appropriate pain medications. Anyone attempting this sort of surgery at home with amateur tools and inadequate drugs would probably be arrested. There are not many ethical concerns about the pain and suffering involved in this procedure, and there are proven health benefits to the patient. There is also the benefit of preventing the birth of unwanted pets that will either have to be killed or will create a serious problem in the ecosystem as a non native predator. Those are the ethical factors to be weighed in deciding whether or not spaying is an acceptable procedure to perform.
The venomoid operation is very often a do-it-at-home procedure, creating very serious concerns about how humane (and reliable) the procedure may be. It has absolutely no health benefit to the patient and can more appropriately be considered a detriment, crippling a healthy animal's normal function. The operation is a serious and invasive one, involving physical trauma and significant post-operative pain that is most often not properly addressed from a veterinary standpoint. Those are the ethical factors to consider when deciding whether or not venomoiding is an appropriate procedure.
It is very true that the commercial importation of reptiles for the pet trade causes suffering and death on a much larger scale than the comparatively limited market for venomoiding. But that wrong doesn't make anything else right. You can't point to one bad thing and say that it makes another bad thing okay. That is an empty and fallacious argument.
It is also true that snakes can suffer in captivity if they are taken from the wild and placed in poor husbandry conditions. In fact they will probably die. It is also true that snakes kept under good conditions with quality husbandry and veterinary care will grow larger and live much longer than their wild counterparts without demonstrating any visible signs of stress due to captivity.
There is a vast difference between captivity that consists of a 10 gallon aquarium and a hot rock and really good quality housing and husbandry. You cannot reasonably discuss the issue of keeping reptiles in captivity without considering the quality of their treatment. The statement that snakes suffer simply from being in captivity is a difficult one to assess because the quality of captivity can vary quite considerably.
There is nothing particularly macho about handling fully venomous snakes as opposed to venomoids. It is so remarkably easy to do that I don't think any special credit should accrue to people who have learned these simple skills. It doesn't take much to figure out which end of the snake hook goes under the snake and which end you should hold on to. Learning to drive an automobile is a much more complex and difficult skill than learning how to move venomous snakes around with good safety tools. It's also statistically more dangerous, and there is no known antivenom for an automobile accident.
Good quality husbandry certainly does not include "stupid snake tricks" where the animal is provoked and stressed to put on a show for its tormentors. Snakes should be moved gently and safely with professional tools in a quiet and nonstressful manner. Macho snake wrestling might be good fun for the handler but it is not in the best interest of the physically fragile reptile. Anyone who finds themselves really pitting their strength and speed against a snake has screwed up royally somewhere in the handling process. I back off long before things get to that stage and gently regain control of the animal in a way that doesn't result in a direct struggle.
Snakes are really not too bright and can be behaviorally managed pretty well just by manipulating their environment. A good example of behavioral management is a trap box. Most animals will happily box or bag themselves when presented with an attractive dark hiding place. This is a much less stressful and more humane method of capture than pinning or grabbing. Being macho is a good way to injure your animals as well as yourself.
Good quality husbandry means always making the choices that are better for the animal's welfare. That means safer and less stressful handling techniques, proper housing and humane care. I don't happen to believe that cutting pieces off of a snake for fun constitutes humane care.