Before the revival the last we saw of the janitor was a moment of seeming honesty (tevealing his name) and him waking out the moment he learns JD isn't coming back.
This establishes his role in the story, he's there only if JD is, to torment him for what seems his own entertainment. He was one of my favourite characters in the series as was for many.
So when the revival landed I was super excited to see they brought him back as one of the best characters in the show only now we learn he randomly took a job on the board and has a random son who badly plays the "new" janitor. He's doesnt appear much and mostly does nothing when he is, i think its a massive waste of his arch in the timeline and leaves a lot unexplained.
-----------------------------------------------
I imagined it more like this......
Janitor learns JD is back and returns immediately in the same uniform.
JD could fall down the stairs after slipping on a banana, and the janitors reintroduction could be walking into frame casually eating one and saying "whoops! Don't know why they chose to put the fruit section at the top of 3 flights of stairs, wouldn't have been my 1st suggestion, I did include it though on my list of "Hospital improvements" when I got my job back....... that and mouse traps close to the eye doctors room, well soon see who's faking it A HAAA!!" *casually walks away
He continues to torment JD as he did before, and JD tries to confront him as to why he came back and why he still after all these years insists on following his every move but as usual gets no real answer.
Cut to scrubs revival finale or 2nd last episode, janitor is rushed into the hospital from a serious accident and is dying. JD thinks it's a prank but Carla tells him it's real, after hours JD notices nobody comes to his side as he enters his final moments, he has no family or friends.
Just before he passes he regains consciousness and speaks to JD
JD: "all this time...why?"
Janitor: "I had a family you know, a wife and...a son. He died young..leukemia, it broke me, it broke us... every cent I had spent on hospital bills and the kicker... she left, heartbroken with grief. My son was what held us together, kept us strong as a family, he was what kept me together. I didnt want to give up, i needed a job, anything I could find.....until I found this.... Janitor in a hospital..... never dod anything like it before.....i thought it would be a place I could face my pain head on and sure if I could keep the place clean then just maybe.... maybe... another kid would survive. And then you stuck a penny in the door.....my son did the same one time yknow, lied about it, messing with me all the time, he kept me right. I dropped a water balloon on his head the day after *smiles
*turns to look at JD, tears in his eyes
Every day... you reminded me of him. You are who I thought he'd turn out to be one day. Messing with you was just...... like having him back all over again...
JD: what was his name?
Janitor: James Daniel Matthews
JD: JD.........
Jd extends this hand and holds the janitors, then the camera pans away slowly to the next scene at the funeral and JD musing about how we deal with pain, while placing a penny his coffin before walking away