This is false. The license for glibc is the LGPL, not the GPL, and the LGPL has an exception to allow static linking without the whole code having to be under the LGPL, as long as the .o files are also distributed to allow linking with a modified glibc ("As an exception to the Sections above, you may also combine or link a "work that uses the Library" with the Library to produce a work containing portions of the Library, and distribute that work under terms of your choice [...] and, if the work is an executable linked with the Library, with the complete machine-readable "work that uses the Library", as object code and/or source code, so that the user can modify the Library and then relink to produce a modified executable containing the modified Library.")