'why' frankly and blatantly, was originally to "get free stuff"
A brief early history:
Fell, Tage, EUOL, Prometheus, Brenna, MoD, Ookla the Mok, GuJiaXian, e3, 42, Skar, Kije, and Dravner (possibly someone I'm missing, but these are a the nicks I can remember) used to all (and some still do) be staff (and at least half of us editors at sometime or another) on a Science Fiction magazine published by BYU called Leading Edge. One day Fell decided he wanted to see if he could get a free copy of Diablo 2, so he called (wrote?) Blizzard to see if he could get a copy if TLE published the review. They agreed. The review was called The Time Waster's Guide
For the next issue, I jumped on the bandwagon, and wrote to Wizards of the Coast, hoping to get one of the three core books under the same conditions. They sent the PHB, the DMG, the MM, the Monster Compendium, the Psionics Handbook, Sword and Fist, and the "Adventure Game." Which the we also published as what became a column called Time Waster's Guide.
Visions of free loot dancing in his head, Fell took the show on the road, and started organizing the web site. For a brief period the column was published in a newspaper in Heber. But the focus was the web site, and it eventually grew into what it is today.