http://www.refinery29.com/2017/11/181630/greta-gerwig-not-get-how-i-met-your-mother-spinoff-reason

"The audience, they're given knobs. They turn the knob to the right if they like it and to the left if they don't," Gerwig explained to Stephen Colbert when asked about the 2014 potential How I Met Your Mother spinoff. "And apparently, they turned the knob to the left every time I came on...so yeah, they didn't like it. At all."

i'm not familiar with the actress - is she as painfully annoying as Ted?

maybe viewers were upset because they already know that the whole premise is a sham and the "Dad" would turn out to be a red herring that basically shows up at the end for a few minutes