Given that 90% of time, developers are working with debug builds, why, exactly, is deploying release builds preferable?
Size, speed, and memory use.
Your users aren't going to need all the debugging crud you work with, so stripping the debug symbols reduces binary size and memory consumption (and therefore increases speed, as less time is spent loading the program's components into RAM).
When your application crashes, you usually want a traceback and the details. Your users really couldn't care less about that.