They are indeed fools. If you look at RFC 3986 Appendix A, you will see that "space" is simply not mentioned anywhere in the grammar for defining a URL. Since it's not mentioned anywhere in the grammar, the only way to encode a space is with percent-encoding (%20).
In fact, the RFC even states that spaces are delimiters and should be ignored:
In some cases, extra whitespace (spaces, line-breaks, tabs, etc.) may have to be added to break a long URI across lines. The whitespace should be ignored when the URI is extracted.
and
For robustness, software that accepts user-typed URI should attempt to recognize and strip both delimiters and embedded whitespace.
Curiously, the use of + as an encoding for space isn't mentioned in the RFC, although it is reserved as a sub-delimeter. I suspect that its use is either just convention or covered by a different RFC (possibly HTTP).