Okay sure, lets not ignore them. He was solid. A decent player for Dortmund in the Bundesliga, a league that in recent years has conned us into transfers of players who were tearing the place up, only to come and be nowhere near the physical and technical ability required for the prem. Pulisic, Werner and Havertz all looked great over there and simply didn't here.
We've got a fairly modest release clause of £35m in Maatsens contract, which for a 22 year old who has just taken his team to a CL final and set the Bundesliga on fire, is surely one of the best deals on the market? Oh thats right, no one wants to pay it.
I think Maatsen is a decent player and I also think it is a shame he didn't get more a chance to prove himself here. But just as you have said people were waiting to jump on him and highlight his failure, many are also too keen to jump on the club and decisions that they have made. He won't get a top English side interested in him and will end up in Serie A or the Bundesliga where he will continue to have a solid career but that doesn't mean we've made a mistake.