Why is that many large curb brandishing riders assume that those of us who ride english have a contact with their horses mouth every second they are riding? I for one vary my contact throughout a hack from light to no contact and full contact with my horse. To me, the contact that creates an open conversation with my horse is far better than choosing to ignore the fact that a horse has a mouth and wants to use it to talk to me. When I engage in more western activities like trail or easy hacks I naturally tend to drop my contact entirely and make a point of training all my horses that a long rein means were just walking, but I can still be trotting a choose to give a horse a long rein in hopes of stretching or relaxing at the trot. I can say that you could ask a western rider to execute a left hand turn and you could ask me to execute a left turn and on the surface they may appear identical, but in reality my horse will know that he is going to make that turn many strides out, where the western horse will probably be informed the moment of the turn. This leads me to believe that in order to get an immediate reasponse from your horse you need a bit that demands it, like a ported curb, whereas I can use my snaffle to explain exactly when and where we are going to be preforming the next action it just requires more warning. Also it is a credit to a good hunter round to have a slight loop in your rein indicating a lack of contact, so you can't say that there is anymore or less contact on these horses than a western horse just because you have a more exagerated loop. No contact is no contact, it doesn't matter if you have a longer rein to prove you have no contact or not, and yet hunters are required to wear a snaffle.
So saying that teaching a rider to have super long reins to prevent any accidental over contact due to the large bit, doesn't do much to educate what many of us have discovered, it is possible to have good hands you just have to really work on it. But once you have completely fluent hands I would say the benefits far outweigh the consequences. Western was invented for cattle drives, long rides over terrain, and I would compare it too a really long car ride with a friend, you don't have to and probably can't talk the entire car ride without getting a really tired mouth. The same can be said with a horse on a long trail, they would get bored of your chatte if you constantly tried to talk to them through the bit. That is a time for you to both relax and just enjoy the scenery. English riding stemmed from creating extreme manuverability and that is exactly what is expected to this day, you cannot have that much manuverability without some kind of constant conversation about what you are doing. So to say it is better to have a curb bit in good hands than a snaffle in bad is like saying it is better to have a cop carrying a gun than a criminal, obviously! But I would think an ideal world would be without guns entirely, and hunters, you can stick to archery, makes you work a little harder for that meal, you might actually get hungry trying to catch it.
As to the OPs question, you might be misinterpreting what i would consider a really good sign. Chewing on the bit means they are thinking about it and what it is going to ask. I favor a bit if I find my horse is chewing on it, it means I woke up their mouth and they are prepared to answer me when I ask questions. I think this is a common school of thought among horsepeople who truly understand bitting. The more slobery and foamy the bit is, the more I know my horse is listening and responding, so I think you are confused about what should be considered a good thing. Many bits are even created to promote salivation. I also think that rather than listening to what everyone suggests you should spend some timre really learning what each part of a bit does, and how different combintaions work. You will start to see that bits with similar parts are going to have similar affects and you don't have to memorize every bit individually, but what the different parts make up when trying to acheive an overall affect. Then evaluate what you want, more brakes, steering, ability to raise the poll, less of any of these things too. Bits may seem confusing and overwhelming but I think it is one of the easier subjects to become well versed in, much easier than conformation in my opinion. By learning about them you can make your own educated decision about what to use on your horse, not let everyone else do the work for you.
The best way to start is to educate yourself about what the difference between a snaffle and a curb so you can see through the mismarketed bits that are out there. Once you know the rules, you will quickly figure out who actually abides by them.