"It's childish, irresponsible and judging by the time frame, even when it 'grows up', it continues to act that way. Looking at it with 'fresh eyes' won't erase the scar this world's people will wreak on the universe, the time lines and... Gallifrey."
When he says 'Gallifrey', it's with a weary resignation, thinking of Mephistopheles Arkadian and how he basically held up to ransom and help damage it irreparably just to line his own pockets.
Then he thinks of Leela and breaks his brief reverie to narrow his eyes at him, figuring out who he is. "I don't have a ship," he said, slightly peevish at the situation he's in. "I was in my office when I was brought through by a temporal rift. I need a lift, not a repairman."
Narvin is not one to buy the innocent act. "And how would you know that you're from the future? I don't recall giving you my temporal coordinates, Doctor."
It made sense. The pathetic affection for Earth, desire to help 'people', declaring it 'who I am' as well as what he does, even fixing his ship on a regular basis.
Oh, it was possibly Iris Wildthyme, he supposed, but even if it was Iris (who had somehow managed to remain sober for a regeneration, definitely a point against that theory), calling him the Doctor would guarantee a reaction regardless.