Former St Mary's stars such as Luke Shaw, Adam Lallana, Rickie Lambert, Dejan Lovren and Calum Chambers moved onto new pastures during the last summer window but failed to make an enormous impact at their respective clubs.
"It (the grass) isn't always greener, that's true," Fonte said.
"I don't wish bad to anyone. Obviously, they were my teammates for many years and above all they were good friends and I wish them the best and I want them to succeed.
"But it didn't happen for them this year and they didn't have great seasons, but you can't criticise, you know. It's decisions, and it's everyone's own life.
"You have to think about you and your family and, obviously, financially it's not everything, but this is our job, it's in a very short space of time, and you need to maximise the best possible way.
"But, having said that, everyone has their own mind and you need to make your own decisions. They've decided to move on.
"I respected their decisions and I wished them well, but the grass isn't always greener. Sometimes you need to think that the decisions you make don't always pay off."