> The goal is to be able to write portable libraries that have keywords.

Well put. Verbose syntax in 177 doesn't worry me, because 177 is meant
as just one interface to the Scheme implementation's underlying keyword
system. Portable code generally has to make a few sacrifices (not only
in Scheme, but in all programming languages). If a library can be used
in ten Scheme implementations instead of two, simply by the library
author typing an extra "call/kw" here and there, that's a huge win.

People writing an application, who only need it to run on one particular
Scheme implementation, are free to use the more convenient syntax given
by that implementation while leveraging portable libraries written using
177. That application can also make use of more complex procedure call
semantics (mixing optional positional args and keyword args, etc.)
supported by that implementation. That's the beauty of interoperability.