I wasn't saying that the prefix syntax was an issue, just that it hampered popularity. Perception ≠ reality, after all. I too quite like the prefix syntax. I still slightly miss the simplicity of some of the Ruby code that I wrote, but the prefix syntax always wins me over; its benefits (macros) outweigh the minor downsides. Especially with []s and ssyntax.
And thanks for the CL thoughts! Regarding IDEs, I myself have ended up working just from the Mac OS X text editor TextMate (using Visor, which puts Terminal on a hotkey), and haven't found it problematic.