I can see how for your average user "guess what I mean" might produce better and quicker results, but for power users (who are entirely comfortable with search syntax, and who sometimes may be searching incredibly obscure things), it produces a worse experience
The only type of search personalisation I want is the ability to exclude certain sites from my search results (bye bye Pinterest, bye bye Quora). Google used to offer that feature, but in more recent years it appears to have disappeared.
I particularly wish Google News Search had a way to exclude media sources I dislike. I am interested in Brexit, so I regularly search on that term, but then I get bombarded with a boatload of sensationalised crap from the Daily Express, a media outlet I'd prefer to pretend didn't exist