It is also much safer to praise a dead artist. Famous alive writer might suddenly turn out to be big fan of some genocidal world leader, embarrassing everyone who loves his earlier work.
Dead people are mostly safe from this, though not completely - some dirty laundry might surface years after death, forever tarnishing the image, but such occurrences are rather rare.
If you are talking about alive people, then no. It was akways the case. The obvious example is Nobel prize laureate Knut Hamsun, who publically praised Hitler. In the soviet Union it was even more pronounced: the government was regularly doing mythbuilding around dead figures, like polar aviator Tchkalov and cosmonaut Yuri Gagarin: they were famous while alive, but became demigods after deaths. You see, you never have to worry that this famous person would do. What if you build up a hero's image, and then he defects to the west?
Also, with artists, only after death you can have his 'complete' works, not having to worry about increasing supply of them, which would push the price down.
Dead people are mostly safe from this, though not completely - some dirty laundry might surface years after death, forever tarnishing the image, but such occurrences are rather rare.