I could not agree more, and the reason is an empirical one: Looking back over the past 10 years, the best and most photos that I've taken were with a simple ~$

I could not agree more, and the reason is an empirical one: Looking back over the past 10 years, the best and most photos that I've taken were with a simple ~$300 Sigma 50mm f 1.4. I do have Canon L glass, but the bokeh and low-light speed just dominate most other considerations. There's also one super important benefit/limitation that I love: With a prime lens, you zoom with your feet. That's not actually bad, you just need to get in people's faces to have them close up. And that in and of itself (often) yields great shots.