I don't think its a matter of possibility more of reliability, and the fact that say an allen bradley plc has a multimillion dollar company behind it with tech support and many engineers to figure out bugs
and arduino that a hobbyist designs can most likely do anything a professional plc can but there's no garuntee that something wasn't overlooked or some bug that would come out later in operation, and then there's no one around to ask for help( other than this amazing forum, which would be amusing to see some industrial companies asking for hobbyist help)