I think this is mainly a USA thing. I've practiced Yoga for years in the Netherlands, and if anything, it is about not straining yourself, or if you do stretch something, to only stretch it when you can be completely feeling and aware of the thing you're stretching. You need that awareness first and foremost, and then the posture.
It's incredibly hard, nearly impossible, to feel and be aware in a body part when it's in pain from overstretching or tension. Consciousness doesn't like to go there, as long as the nerves are occupied with sending pain signals, they're not doing much feeling. If you ignore or block the pain you're not being aware, but if you do, the pain is "louder" than anything else, so you're still not getting much.
It's stupid and useless. The goal should be the awareness, so you're much better off doing simple postures, or simplified versions of complex postures, or just see how far you can go while still being comfortable and aware.
If you practice it this way, you'll know when you're going too far, because your awareness will fade (you'll often just realize it in hindsight, though, in the moment, you're not aware that you're not aware, just like Dunning-Kruger) and if you don't, that's what the teacher is for. S/he will pay attention to the students and notice when they're more involved with doing a posture than with paying attention to what all there is to feel inside their bodies.
I just can't get my head around this, to get all the benefits of Yoga, you can just stick to the simplest postures and do them a lot (unless you're injured in which case you do them even simpler, the Sawasana is just lying down flat on your back, so there's always that one). If you try postures that are too complicated or straining for your body-flexibility, you'll get nothing! Except injury! It's just stupid, these supposed "experienced" Yoga practitioners, "advancing" to more and more complicated postures, I suppose every time they feel "comfortable" in some posture they move on to something new! They're missing the whole point! Feeling comfortable? Good. Everything you did before was not Yoga, but warming-up and stretch exercises. It's Yoga when you can relax in a posture, without strain, without pain. And if there's some posture for which that seems impossible to you, do a different one. It's okay, they're not "better" than the ones you're comfortable in.
It's incredibly hard, nearly impossible, to feel and be aware in a body part when it's in pain from overstretching or tension. Consciousness doesn't like to go there, as long as the nerves are occupied with sending pain signals, they're not doing much feeling. If you ignore or block the pain you're not being aware, but if you do, the pain is "louder" than anything else, so you're still not getting much.
It's stupid and useless. The goal should be the awareness, so you're much better off doing simple postures, or simplified versions of complex postures, or just see how far you can go while still being comfortable and aware.
If you practice it this way, you'll know when you're going too far, because your awareness will fade (you'll often just realize it in hindsight, though, in the moment, you're not aware that you're not aware, just like Dunning-Kruger) and if you don't, that's what the teacher is for. S/he will pay attention to the students and notice when they're more involved with doing a posture than with paying attention to what all there is to feel inside their bodies.
I just can't get my head around this, to get all the benefits of Yoga, you can just stick to the simplest postures and do them a lot (unless you're injured in which case you do them even simpler, the Sawasana is just lying down flat on your back, so there's always that one). If you try postures that are too complicated or straining for your body-flexibility, you'll get nothing! Except injury! It's just stupid, these supposed "experienced" Yoga practitioners, "advancing" to more and more complicated postures, I suppose every time they feel "comfortable" in some posture they move on to something new! They're missing the whole point! Feeling comfortable? Good. Everything you did before was not Yoga, but warming-up and stretch exercises. It's Yoga when you can relax in a posture, without strain, without pain. And if there's some posture for which that seems impossible to you, do a different one. It's okay, they're not "better" than the ones you're comfortable in.