There's merit to both arguments... such a high calorie intake may not be good in the long run, but I also need such a huge intake to gain weight because of how much I unconsciously burn in a day (on top of already having a lightning-fast metabolism).
I'm a drummer, and I fancy myself a Keith Moon type of drummer. That means an all-out assault on the drums for prolonged periods of time. I can't even run 50 feet on account of underdeveloped lungs--the result of growing up with four packs of secondhand smoke a day--but I can drum like there's no tomorrow. In fact, I can do Keith's fastest stuff for three uninterrupted hours at a pop.
When I'm playing my drums is nearly the only time of day that I'm sitting down. If I sit down at any other time, I'm always tapping my foot, playing drums on my legs, or simply bouncing both of my legs up and down. A doctor once told me I probably burn around 500-600 calories a day just by dong that (which seems like a high number until you see just how much I do it). And I can't tell you how many times I go visit my mom and hear:
"Stop it! The entire floor's shaking!"
"Stop it! The table's shaking!"
"What is that noise? Are you banging on the counter? Stop it!"
"Was that you banging on something?"
"The couch is shaking all the way over here..."
And then there's just the stare. You know the one.

On top of that, I never (ever ever) sit down when I'm on the phone. I can't sit and talk, I have to pace to get the brain going. Same with when I had classes to study for. I'd take the book, walk around with it, read a section, and say it back to myself like I'm in a tutoring session. I work as a university tutor (psychology) and I'm always at the board, drawing stuff, lecturing, or dancing around like a mad fool so that students remember concepts. I may sit down for 10 minutes of my workday, and I never tire of standing.
Have you heard of set point theory? That our bodies have a comfortable weight range that they'll maintain if one eats when they're hungry, stops when they're full, and gets moderate exercise? I think mine is around 145 because that's where I was for 12 years of my life before anorexia took hold. My ravenous appetite right now might be that my body is trying to get back to its set point after years of being so low. Set point is like a thermostat: your body craves extra calories when you dip below, and you won't have much appetite if you go above (until you dip back down to the preferred weight). Of course, my ravenous appetite might also be from the start of HRT, who knows.

I started HRT at such a low weight that it's tough to tease one from the other now.
So after I gain 5 to 10 more pounds (putting me at 145-150) I'll see if my appetite takes a nosedive.