Hey, there! I don't know your dad, but I also grew up poor and am currently working my way through school.
First of all, you are correct to be proud of your father, and you are also correct to take a responsible outlook on your life. That sort of attitude will get you far. But you really just aren't grasping the arguments people are putting out to you. Hopefully my perspective is helpful for you to understand why people are disagreeing with you.
Let me break down my budget for you. I currently make $13/hr. After taxes and health insurance (which I am fortunate to get an an affordable rate from my company) I bring in $1600 net every month.
I am very fortunate in that my work provides a free place for me to live. Therefore I do not have to worry about rent or utilities, which is a huge boon. I am also very fortunate to live in an area with a very affordable community college. The tuition and books every semester runs me around $2000. Going three semesters a year, this comes out to almost exactly $500 a month. Food costs me about $150.
My community college is about 25 miles away from where I work and live, so I have to drive a lot. I spend about $200 a month on gasoline, $100 on insurance, and $150 on my auto payment. Should have saved up and bought a cheaper car cash you might say? Well, I had a cheap, reliable car. Someone t-boned me and ruined it. I got $2500 for it, but you can't buy a reliable car for $2500 so I had to take out a loan to cover the other $4000 I spent. So there was step one pushing me into a shitty situation.
Out of the $500 that is left over, most goes to service my consumer debt, of which I have about $4000. Again, you might criticize me for using credit unwisely but I can assure you that nearly all of that was imperative. I have only had free rent for less than a year, meaning my budget was inadequate in the past and I financed car repairs, medical bills, anything unexpected and unavoidable on credit. Because I literally had no other choice. Each of these situations has, in the past, caused me to stop going to school for a short time while I got my finances together, which included me working multiple jobs at the same time. Never janitorial, but some pretty shitty work nonetheless.
So here I am, 26 years old, and I'm working my ass off 40+ hours a week on top of going to school full time trying to make it happen. And it will happen. But I will not finish school before I'm 30, even in the best case scenario. I probably won't be out of debt until a few years after that (once I hit university tuition jumps to $10k+ a year for a couple years and I will almost definitely have to stop working so much in order to succeed, meaning large student loans). The idea that I could be flying around in a Learjet if I only I bucked up and worked a bit harder, or that I could pay for my tuition by giving up soda is so fucking ludicrous that it's hard to even take you seriously.
You known how I can tell you don't have any perspective? You haven't said a single thing about yourself. It's all "My dad did this" or "my dad did that." You obviously had a father who kicked ass and did very well by himself, and I don't mean to discount that, but what about you? Do you really think that if you were born poor and to lazy ass parents that you would be in the exact same place you are right now? Think of every dumb mistake you have ever made. Every time you made a poor decision and it somehow worked out ok for you. There is somebody out there that made that same decision and had it blow up in their face. There's somebody who wasn't given the opportunities you were and is having to scrap it out tooth and nail. Be grateful for how fortunate you have been, and don't patronize them with stupid ass arguments about giving up soda and paying for university tuition with the difference (I don't drink soda FWIW).