That's not true though. They should have been winning trophies with the team they've had the last 4 years. They have been well capable and probably still are. Did they need to sacrifice all long-term thinking for possibly a trophy or two if it could hasten the decline in quality of their squad and ability to compete at the top end of the league, as Jose has proven so adept at doing?
They're Spurs, not United. If this goes south at some point, as it likely will, they can't just spend their way back to the top 4 again. They'll be in little better a situation than ourselves and Leicester have been if their squad has been broken up and the chemistry ruined as we've seen at United.
They're already on the way down and need someone with fresh ideas and a plan to build another squad with great chemistry etc as Pochettino did. Ideally they'd be looking at finding the next Poch, the next Klopp. Mourinho is just likely to set them back years and years once he has his way with them. One thing Mourinho guarantees is a short-term approach to everything, as he has nothing to prove and doesn't really care about the clubs he manages. He doesn't necessarily guarantee success either. There's a bit of an assumption that Spurs have just won the league/CL next season with this appointment because supposedly Mourinho guarantees it. They'd better hope for some kind of success because it'll come at a huge cost in the end.