Hakimi completed a €60m move to the French capital on Tuesday after just a single season with the Nerazzurri.
The 22-year-old joined Inter from Real Madrid last season following two seasons on loan at Borussia Dortmund and was instrumental in the Nerazzurri winning a first Serie A title in 11 years under Antonio Conte.
Hakimi made 37 Serie A appearances and scored seven goals from right wing-back.
Financial restrictions arising from the coronavirus pandemic left Inter cash-strapped, leaving them with no choice but to cash in on one of their prized assets.
"We begin a season that will be difficult, as usual," Marotta said during the unveiling of new manager Simone Inzaghi on Wednesday.
"We are going through a difficult and in some ways disturbing time after the pandemic, also as a result of the world economy. As a reflection, football is now looking for a sustainable model.
"Surely, Inter want to continue on the same path as last season, looking at the economic and financial aspects. The owners want to build a competitive team, they've invested over €700million and football is paying the consequences of what has just happened.
"It's unthinkable to ask for the same efforts. We made painful choices like the one of selling Hakimi but always trying to give continuity."
