Why hasn't Wildfur ever bonded with the keepers of his colony? Hard to believe Shrewbelly wouldn't give him comfort and support he needed. Also - why isn't Blueflower a keeper, too, given her love for babyraising? Has she never been keeper?
At first Wildfur would have gotten along with Shrewbelly and his mother just fine. It's only after Patch's traumatic death would things have changed.
It's important to remember that trauma effects everyone differently, and those with trauma sometimes cope in unhealthy ways. I believe there was a real effort made to reach out to young Wildfur, but it wasn't the kind of help he wanted or needed at the time. Patch's death was not handled well, as it was a combination of a little bit of everyone letting their guard down and 'wrong place, wrong time'. So when it happened, there was a lot of accusations thrown around, including directed at Wildfur in the heat of the moment.
Crowstalker and Blueflower's relationship already wasn't great, Shrewbelly is only one cat in charge of all Keeper duties, and Wildfur was just a kid who lost his brother. Add the guilt, shame, and feeling like the Colony secretly blames him for what happened, (why wouldn't they? He blames himself,) and Wildfur is left with nothing but bitterness.
The main reason Spottedshadow and Wildfur connected so easily is due in large part to the fact that Spottedshadow didn't know about what happened. He didn't have to feel all the shame and guilt around her, but she was kind and understanding regardless of not knowing.
It's messy. And though these cats make a solid effort, they unfortunately don't have therapy.
As for Blueflower, wanting to have kittens, or even hanging out with kittens from time to time and wanting to be a Keeper might seem synonymous, but it's really a few giant leaps apart. Being a Keeper means taking care of everyone's kittens all the time, learning you oral history and legends, making dens, walls, tools and crafts, and spending a lot of time either gathering supplies or being in camp. Plus with the supersition around Marsh Colony being closer to death, and the Spirits Beyond, becoming a Keeper is not a job most cats want in their younger years.
And especially after what happened with Wild and Patch, Blueflower feels like she failed as a parent. And in that headspace she wouldn't dream of becoming a Keeper. She's the least worthy cat for the job, in her own mind.