I am what you might call an autodidact. When I observe an institution isn't sufficiently good, I pivot and fulfill my requirements elsewhere, for example by reading a book or meeting passionate people informally. I do not believe that this autodidacticism is great efficiency-wise, but often it's unfortunately better than alternatives.
When evaluating the earlier poster's anecdote of teaching 180 adults, of course it's very unlikely that she/he had the terrible luck to draw 180 (or even 100) genetic freaks who were born with terrible attitudes. (And even if she/he did, just wait a semester and problem solved!) Far more likely to me: at least one major institution failed them along the way. So it is clearly useful to identify which ones failed — especially if it's the one you're in, as that's the one you have most control over. (Teachers in particular have a position of power in the classroom.)
(The power of institutional analysis is you can completely replace the people in them, and they'll still function essentially the same.)
More important — if you realize that your approach is clearly unsuccessful, I think you need to stop, reevaluate and probably pivot. Be open to shattering your worldview. Rather than plod on stubbornly in a direction you know leads to abject failure, because most people around you are willing to fail miserably in the same way. (Or because "But it's not in my job description!") I do not intend to be such an extreme romanticist of failure. In fact, today I happened to institute post-mortems at work, to identify our little failures. Not to blame, but to improve.
It is important for teachers to have good attitudes, and it's disheartening to meet those ironically unwilling to learn. But I've met wonderful teachers.
It was an assumption based on your words (epsilon delta proofs and whatever else we did were tedious) and my experiences with people who dislike classes of proof-based math. No projecting here--I enjoyed my analysis class. We a fair number of epsilon-delta proofs.
My issue with your initial response was that you were implicitly blaming the class for being boring and causing you to lose your enthusiasm for math. My point is that its not their job to foster your enthusiasm, especially at that level.
Now of course, we should always be re-evaluating how subjects are taught to make sure information is being conveyed as best as possible. But we have to resist the temptation to immediately blame a student's failing (by any measure) on the teacher being inadequate in some way. If we start the conversation on that note then the space of potential solutions becomes severely restricted.