Fun and sad. Garbage collected languages like .NET, Java, and Go are slow compared DIY languages like C, Rust, and Swift. So, no wonder the Windows team dislike them. However, it seems the Windows team had to live with a React start menu for quite some time. How does that fit into the over all battle between the teams and UI frameworks?
That wasn't the issue. The problem was that most of Windows system utilities are not managed, but the WPF move was trying to make a patchwork quilt of managed vs. unmanaged utilities, making the entire system very difficult to reason about and introducing regressions constantly. From the Windows Team's perspective, the .NET people just made a mess out of everything they touched.
Perhaps if WPF really did stay at the presentation level, or used VMs or something to keep it away from the Windows core, it would have panned out better. But is it goes with "paradigm shifts", when a company thinks it has a great idea, it wants to suddenly do that great idea everywhere.