I said NO because some passenger trains travel too much distance or have too much journey time to be feasible to be MEMU/DEMU, for example 57477/8 TPTY-KRYP passenger travels 538km in almost 17 hours. MEMU/DEMU rakes can't seat as many as the normal train seats. So, I think it is okay to convert Passenger trains with small journeys to DEMU but Trains having long journey shouldn't be converted.