A big part of the draw of SNL in the past was that it brought out new talent. If you weren’t living in New York or LA or Chicago in the 80s and 90s you weren’t really aware of the SNL cast before they were the SNL cast. And some of the material was great and some of it was just okay and some of it was outright bad. But it was a bunch of new people to fall in love with.
But that started to change in the late 90s and early 2000s. At first it was because of the alt comedy boom. Lorne wasn’t just picking from improv theaters and the occasional stand-ups but people like Janeane Garofolo and Sarah Silverman who were proving themselves elsewhere. Amy Poehler was probably the most high profile example of this, having built the UCB herself. Then the internet made this effect even worse. Kyle Mooney had a huge web following, Kate McKinnon had the Big Gay Sketch Show.
And in addition to those cast members having other avenues to put out their work (thanks to cheap digital filming, SNL cast members now regularly appear in amazing non-SNL projects all the time) there are also a million avenues to discover other amazing people putting out just as much material.
I guess my point is, in 2015 I’m really running out of reasons for Lorne Michaels to have any input on my taste in comedy.