Why
From OFLB
Here are some use cases that illustrate why the Open Font Library exists (and what features it should have).
Mary, soccer mom and scrap book hobbyist, is searching the web for "free fonts". She finds OFLB and wants to browse all the fonts in the library at once, and quickly download all the files for the dozen typeface families she thinks are cute as ZIPs. She sees something about how these fonts are free as in no price, but also free as in she can change them, and she bookmarks the site to learn more about all that later: they're libre/open fonts.
John uploads a typeface family with several font files and a PNG "specimen" example of the font in use, as a single .tar.gz file. He adds some "fontlog" style information in the description field of the form. He expects the site to make everything drop into place - so he can link to his font via @font-face, so the PNG image will be displayed in the page when people browse to it. John is pleased to see the information he added to the description is available as a "fontlog.txt" text file in the "complete font" zip. He later uploads a single font file with a bugfix to replace one of the fonts in his tarball.
Alice, designer, is looking for a quirky handwriting font and comes across OFLB. She's intrigued and impressed by what she sees and wants to learn more.
Bob, designer, has done a typeface for a project and wants to contribute it cos it's kinda cool
Sanjay, who works at Institute of Linguistics in Bangalore, wants to add a family of typefaces for an Asian script that his team have worked on for the last five years. There are multiple weights and variants.
Charles, a retired high school teacher, is making fonts for fun and posting them on his homepage with a semi-free license. Libre/open font activists email him and suggest he use the OFL or GPL-FE-etc or MIT/X11 and upload his fonts on the OFLB. Charles isn't sure about this so he visits the OFLB website. The activist wants Charles to see he'll be part of a community that recognises his work, contributes quality additions, and so on.