If you've used Google Search then the autocomplete feature will be familiar to you. It tries to guess what you're looking for before you type it, so you don't have to spend a few fractions of a second typing the whole thing out. While autocomplete includes many things, Google specifically removes certain words and phrases for a variety of reasons, including piracy, and Kodi is the latest victim.
This doesn't alter the contents of the final search (though Google often uses algorithms to demote copyright-infringing content), but it does mean Google will pretend it doesn't know what you're talking about if you type in phrases like 'pirate b', or 'bittorr'. It's basically the digital equivalent of sticking your fingers in your ears and going "lalalalalala".
The logic behind removing Kodi from autocomplete is because of the platform's association with copyright infringement. The fact that the developers at the XBMC Foundation (which manages Kodi) make a point to disavow piracy whenever they get the chance is irrelevant. The open source nature of Kodi's media centre software means third party developers can produce illicit addons that let users access copyrighted content without paying for it.
TorrentFreak points out that if you type 'kod' into Google, it'll suggest things like Kodak, though the filter doesn't extend beyond the initial Kodi brand. Typing in partial names of the best known Kodi-based piracy addons still triggers the usual autocomplete recommendations, as do competing products that also get exploited by pirates, and even 'Krypton 17.6' which is a recent Kodi build.
While Google doesn't usually document the words its removes from autocomplete, it has confirmed that Kodi was deliberately removed from results. The XBMC Foundation, meanwhile, is disappointed in the move, with President Nathan Betzen telling TorrentFreak:
“We are surprised and disappointed to discover Kodi has been removed from autocomplete, as Kodi is perfectly legal open source software.
We have a professional relationship with the MPAA, who have specifically made clear in the past their own position that Kodi is legal software.. We hope Google will reconsider this decision in the future, or at a minimum limit their removal to search terms where the legality is actually in dispute.”