Enforcing 'no space before the non-blank char on every line' is orders of magniture more difficult than 'indentation is 4 space'
Is it?
find . -name *.c | xargs perl -ne '/^\s*/ && $& =~ / / && do { print }'
compared to
find . -name *.c | xargs perl -ne '!/^(?: )*/ && do { print }'
Of course both will fail on Wine style function header comments but then you got what you asked for above.
Anyway. I fully agree what you (Dimitrie) that the point of indentation is to make it human readable not easy for tools to verify.
In fact I think I agree with almost everything you have said on the subject. So for once we agree. :-)