It may be because Google makes its income from advertisers, and the buyers are mostly on .com websites; or there may be some other reasons; but there is a distinct and quite apparent scarcity of .org and .edu results in Google returns. They appear occasionally, but not - apparently - in proportion to the number of such sites on the web.

The sparse results for .edu sites can possibly be due to many such sites being "internal" to universities with passwords required for access - i.e. they're "private networks."

Real reasons for anything Google does are "trade secrets."

It is notable that the 'cat started appearing in Google hits more often pretty much simultaneously with the agreement to allow their ads here. (?)

One of the criteria Google admits that they use is the number of links to a site, from other "popular" sites. Since all the good folk folk are already here, there's no reason for very many people to link to the 'cat - at least from sites where all the "kids with money to spend" hang out.

John