From the moment he first stepped on board Voyager, Harry was a Senior Staff Officer, a trusted Senior Bridge Officer, and the Head of Department for the Operations Division, AS AN ENSIGN.
Harry was the Voyager counterpart to Miles O'Brien, yet you don't see people whining about 'poor Miles'.
Harry didn't need a higher physical rank because he was already in a position of authority, and it was a mistake to make a joke out of his lowly physical rank because it cheapened his character and role on the ship.
The only time I think about "poor Miles" is in the context of "Poor Miles, being married to Keiko the Shrew, who mocks his choice of food, begrudges him his recreation time with Julian, and doesn't even pronounce his name correctly."
Just watch how Janeway welcomes Harry to the bridge the very first time. "Ensign Kim, this is your station." She seems a bit condescending, or patronizing, or maybe it's just her maternal instinct dealing with a puppy dog. I dunno.
Considering that Harry's mommy contacted Janeway because her little boy had forgotten to pack his clarinet, it's not surprising Janeway might have been a bit condescending to him.
I wonder if Mrs. Kim sewed name tags on all of Harry's other belongings?