Unless he came in and was one of the best 5 players in the league, would anyone pay 7 figures for an average-good championship level 29 year old they could have got in the summer for free, and only has 12 months left on his deal? No chance. Not to mention some significant off the field baggage/history.
Also I agree with you that he's a good player, and more than good enough to make a big impact on our side. However with such a harmonious squad, does someone coming in who was sacked by his last club help? Maybe what happened isn't that bad and he's a good guy, if so would be absolutely fine, but you don't know that.