There's a few reasons why you might think this.
1. We only signed him last summer. Give him a chance.
2. Let's actually get our coaches to coach and improve him, instead of giving up on him and getting a replacement already
3. He's shown promise, and our team has more holes than a swiss cheese. Why not give the RB spot to Dalot for now, while we throw that 50m into the pot and fix our gaping left and right wings? Or replace Eeyore up front? Or sign some of the 2-3 midfielders we need. We have other priorities, it's like your house being on fire then being pissed off because the windows need cleaning.