I believe that Tottenham management is scared of what will be the outcome of the club next season, especially their performance in UCL. UCL isn't a weak competition, therefore, allowing Anga to continue as head coach can bring catastrophe to the club next season. Of course, only the change of the coach wouldn't make any difference but all loop holes need to be covered.
Tottenham's performance in the Premier League this season was terrible, we have seen that. But we should not forget that Tottenham won the Europa League title with the help of Ange Postecoglou. Do you remember the last time we saw Tottenham win the title?
Firing Ange Postecoglou cannot be a solution. By firing Ange Postecoglou, Tottenham management is trying to cover up their weakness. Tottenham should definitely strengthen their squad. This team is quite weak. Even Newcastle's squad is stronger than Tottenham.
If Tottenham management does not take the necessary steps to strengthen the squad, we will not see a better performance from this team next season. Changing the coach cannot be a solution. Strengthening the squad is now very important for Tottenham.