1. Passcomplexity breeds tech debt
"I’m often skeptical of the desire to create a lot of passes… we were paying a lot of interest on tech debt because features were put in the wrong pass." — verdagon
2. Language constraints force passes to intertwine
"I wrote a small nanopass‑style compiler… lots of redundancy, and hard to debug because it wasn’t clear how the passes interacted." — armchairhacker
3. New research looks for alternatives (e.g., egraphs)
"It’s the first I’ve heard of them. Looks like the research goes back to 1980, but good libraries seem fairly new?" — skybrian