Empoli sold the goalkeeper to Spurs this week for €20m.
Galli told TMW: "When they go abroad I'm always disappointed also because they are replaced by foreign goalkeepers. We have many young players ready for the big leap but it takes courage.
"...I think the Italian school is the best. (Wojciech) Szczęsny was mediocre and became a regular for Poland. Allison was a mediocre and became the strongest in the world. (Mike) Maignan became a regular for France.
"It means that our trainers are good and I'm p***ed off."