Why aren't installed binaries stripped?

[FX]

When GCC is installed using “make install”, why aren’t some of the installed 
binaries stripped? (at least, as of 4.8.2)
On a x86_64-unknown-linux-gnu multilib install, stripping the following 
binaries makes the overall size go down from 479 MB to 204 MB (57%):

  $prefix/bin/*
  $prefix/libexec/gcc/$host/$version/{cc1*,f951,collect2,lto*}

I can understand that debug builds are built with full symbols, but why don’t 
we strip binaries when we install them on release version?

FX