Chris Wood and Jay Rodriguez struck to give the Clarets a first win at Old Trafford since 1962 as the injury-hit Red Devils delivered another flat performance.
Ferdinand is concerned about the direction the club is heading and insists the club need to act to arrest their slump.
"I can't defend this. What has been invested?" he said in his role as a pundit for BT Sport. "These young kids now in schools around the country, they are not going to be wearing Manchester United shirts.
"They are not going to be wanting to come here and support Manchester United based on what you are seeing out there. It's just not going to happen, fans are walking out after 84 minutes!
"It's an embarrassment. People at the top need to look and see this and make changes, put a plan in place that people can sit there and see where we are going now. I don't see it."
Ferdinand, who had urged the club to appoint his former United team-mate Solskjaer as permanent boss after his outstanding spell as caretaker, believes United's problems run deeper than just the manager.
"Since that point (Solskjaer's permanent appointment) it has been a really rocky road. The problem is it is not one area of the club, it's everything that needs pulling together and it will take someone coming in with a vision to make that happen.
"Whether that person is in the building at the moment or not I don't know. The recruitment over the last seven years, (Marcos) Rojo, Falcao, (Marouane) Fellaini, (Matteo) Darmian, (Memphis) Depay, were these players ever Man Utd players really?
"Who is buying these players? Even now, you look at the team, £600m or so spent and probably the four most impressive players this season have been homegrown. That speaks volumes about the recruitment and how shoddy it has been."
United have been through four managers since Sir Alex Ferguson's retirement - when Ferdinand was still in the playing squad - and the former England captain believes the club is on an alarming "downward spiral".
"In the grand scheme of things, mistakes have been happening so often before this and to fix it is going to take time," Ferdinand added. "But these fans are not giving it time, they are singing songs and leaving early, 84th minute, it is unheard of at this stadium.
"People need to sit and watch this, get a video tape and see these fans leaving with the disdain on their faces. This is an embarrassment. There is no other word for it. This is the team that I love coming to watch, I loved playing for. The difference, the downward spiral in this short space of time, it's only seven years, has been remarkable.
"The results that are being churned out are not good enough. I played with Ole, he has had some big players injured but still, the money that has been spent on this squad, there would be more waiting in the wings."
Former England striker Peter Crouch added: "This squad has got to be the worst squad in the last 30 years, it is nowhere near it.
"You can blame the manager but this squad, you look at the options off the bench and they are miles off. It's a sad state of affairs. This is one of the biggest clubs in the world and it has been run badly, it has been mismanaged. I don't know what a Manchester United player is any more."