Instead replace that statement with "We make money by not giving you this function, so why make any changes?"
Just to be clear, I don't make any money from the site. The Mods are all volunteers.
I did leave out a chuck of context that I thought was understood, and maybe some of what I meant was thereby lost.
As Morrus said, the real search feature (which is native, not Google-driven) works pretty well, but kills the server if too many people use it. It wasn't pretty when he did turn it on for all users.
The Google method works well on SRD sites, because they have highly structured and controlled data, and much less of it. For large message boards, it is a slap-dash solution*. We want you to get the most out of the site, though, and don't want to trick you into buying an account just for search. We mention the Google method when the question comes up, so at least you have some option.
Let's say he did put in a Google search box. Very quickly, folks would find it kinda sucked. They'd say so, loudly. "Hey, you gave us a feature, and it sucks!" He'd say, "Well, you could pay for a better search...," and everyone would grump at him for bait-and-switch upsell business practices.
To me, that sounds like a worse situation for everyone. Why spend time or money to include a feature that works poorly, is already native to the user's browser, and makes you look bad to your users to boot?
*My personal experience is that it gets you a lot of false-positives from Google. If you know exactly what you're looking for, and it is recent, what you want will usually be one of the top hits. Otherwise, you're going to be wading through a lot of search-noise. And Google cannot handle searching for a post by a particular user well at all.