DMPCs aren't always a bad idea. If the players all want to play meleers, having a skillbot/healer DMPC following them around and being useful is a grand idea.
And sometimes (mostly my group for some reason), the players really LIKE an NPC the DM has made, and so asks them to tag along and be with the party as party members. Really, I've had players drag NPCs along and force me to flesh them out into full characters who chill with the party and be party members. Strange, but true.
All that I say applies only to myself. You author your own actions and choices. I cannot and will not be responsible for you, nor are you for me, regardless of situation or circumstance.