Half and half...
Yes, you should be prepared to work hard to earn your way through life, and this includes flying. You can do the math, if you're satisfied with the ratio of the reward, then you should be fine. Of course you're going to be given the ick jobs, a lot of us were. I did my share of ick jobs, but remind yourself that the next person to come along after you, gets the ick job, and you move up. At lease you have the job.
If you genuinely feel exploited, that's not good. But keep it realistic, you're worth 3-5 per hours, and the plane is 100 plus and hour. 20 or so hours of slaving for an hour of flying.
Now, when your work changes to actually be maeningful work ON the plane, things change again. you want that work, that's how you learn about planes. I spent a lot of my early days, on my back filthy under a plane, cleaning it, and thought myself lucky. I flew a lot in return, and I really felt that I won the deal - I never counted the hours, just the owner of the plane's satisfaction - They did not seem to count the hours either, so I won.
Funny now, I own two planes, and can't find a single kid who would like to trade cleaning them for flying - go figure, I guess they're in the computer flight simulator instead!
The plane owner just wants the job done, and no grumpiness. If you leave him smiling, he should leave you too smiling too. Hopefully you learn along the way - that's why you're doing it -right?