I think the thing is Bellamy was a veteran. trust me in that I know that Bellamy played like hot garbage last year. But I can honestly say he was adequate this year.
Now just in seeing Wims, I can tell you he feels like he has more upside than Kevin White does.
Usually then when you see stuff like this, it's because Wims was having a hard time learning the route tree for his position. However game like that last one versus Minnesota will earn him some playing time and consideration, especially given that Kevin White is likely gone at the end of the year, and possibly Bellamy with him.
Wims moves up to the Bellamy role, and Bears draft another receiver to fill out the corps...