It does have it's bad spots, but I really don't see how something can "suck" when 1) it works and 2) every single other alternative is light-years behind.
If you are coding and not working with designers or using Blend, sticking with plain-old C# is better. WPF/WinRT/Silverlight are just great APIs, that they are somehow associated with XAML is orthogonal (my personal opinion, not speaking for my employer).
