Ten Hag will continue to be mentioned frequently and repeatedly because he had his chance to change things and he squandered huge funds trying to reunite with his former players at Ajax and as a result made situations worse at Manchester United. He will be dragged everytime Manchester United problems are being discussed because he contributed to the problem instead of solving it.
I think it's very natural, success and failure will always be remembered by everyone, especially Manchester United is a very successful club before. Ten Hag is still part of this season, and it makes sense if fans continue to associate The Red Devils decline with him. Besides, Ruben Amorim also has not managed to fix the chaos inherited by Ten Hag, because of that Ten Hag name is always fresh in the memory. I think next season Ten Hag name will start to fade, with Ruben Amorim starting to overhaul the depth of the Manchester United squad and starting a new era.
After retirement of Sir Alex Ferguson Manchester United have 10 coaches in last 12 years which is telling all story of their success after this golden era things have never been on track, and they are facing many on and off the field issues which re preventing them from having consistency and success.
Current season performance is going to be one of the worst into their history Ten Hag era was also on same level, but now things are taking changes even their performance in Premier League is still not good, but they are doing good job in UEFA Europa League which is giving them some encouragement. Many are expecting things could be on good level in next season because Amorim is having good chemistry to settle problems but still these are too early because currently their focus is having good results in this event which can turn the tables for them.