Short version of the explanation, "It's not her, it's us." But the show may come back in syndication. The official statement from Hallmark:
Hallmark Channel is in a phase of true transformation to a much more diversified portfolio of family friendly entertainment that includes original movies and acquired series in addition to original primetime scripted series and a full original daytime line up. With so many talk show offerings in the daypart, particularly in broadcast syndication, Hallmark Channel has decided not to greenlight a second season of its Critics Choice Award nominated talk show, Marie, starring Marie Osmond. As the network examined and explored its work in daytime, we determined that the best direction for this daypart is to offer quintessential lifestyle service shows that inform and entertain our viewers with how to, tips and ideas for living their best lives. We also find these types of shows best serve today's demand for digital video.
We are extremely grateful to Marie Osmond, whose immense talent and dedication to excellence is unmatched in entertainment. Marie is a consummate professional and outstanding human being in every way possible. We have enjoyed working with her on the talk show and know her passion to create an offering of such high quality will find great success in syndication.