Nowadays companies tabulate their applicants: What are his skills and how good is he at them.
If you or your letter don't fit into that bureaucratic scheme, you're out.
(One company asked me three times to rewrite my cover-letter and reapply. In the end, the outline of the cover-letter was to their criteria and they didn't take me anyway.)
I know a guy who's a manager at a major company. He told me that he thinks this system sucks as some skills and attributes just can't be classified as hard numbers. He prefers to read the cover-letters himself instead of just getting the yay or nay from HR.