I get the impression you deliberately misunderstand the issue.
The issue is precisely the indirect nature of the license grant. If IBM would clean up the header files that does give legal clarity (as opposed to anybody else changing those legal statements on the files).
People don't question the value of what Apache projects do. That is indeed much more than the single act of IBM clearing up the legal status of the files by cleaning up the headers.
Various Apache project members have stated on the mailinglist they feel not cleaning up the headers is a problem and they don't want to touch any of the files till IBM does that.