Yep. That explains how he was able to focus full time on Dropbox then. He must have always had a trampoline to bounce him back up should he fail. I know it was funded from the beginning most likely, but there had to have been a time before it was funded.
I've been thinking about how to respond to this for a little while, because I'm a bit biased and I don't want to give away to much information about Drew's personal life.
I lived with Drew through college and a bit after. The thing that grew into Dropbox was started in an apartment that I lived in while Drew and I were working at a different startup.
While I would say that I regret not being in the financial position to quit my job and help Drew out early on, I don't think he was able to do it because of his privilege. I also want to call out that I'm struggling justifying that last statement, because I know what a privilege being white, straight, and upper-middle class in America is. That privilege totally helped getting into MIT (by virtue of going to a good high school and so many other things). But, I'm pretty sure he didn't rely on his parents for cash. He probably just stole my leftovers out of the fridge. :)
The fact of the matter is that he's scrappy and smart. During college, we were both presented with an opportunity to make some side cash. Drew took more advantage of it than I did, and it was smart of him. He banked his own cash and lived cheap. Maybe he graduated with less debt than I did, and maybe that helped, but I think that would be the only leg up that he had.
I know it's fun to be envious of rich people, but I grew up in poverty, and so far I've earned myself 5 years to focus full time on my stuff. I know it's a little harder, maybe, but all I had to do was go to work first. Most people go to work anyway.
Maybe I did come off as envious, but I'm not angry, or sad, or feeling like I don't have opportunities to be a successful startup founder myself. It's just that you do often see a pattern among founders. It's so common that I've started noticing it.
It's certainly not true that you have to come from a privileged family to be a successful entrepreneur. Look at examples like Larry Ellison.
It seems like your question was set up to confirm your conclusion. If you had instead asked how Drew was able to support himself, you'd probably get a more accurate answer.
I feel like most all of us (and especially those of us in the USA) have a fairly decent "trampoline" to fall back on. Most of us have enough skills to go out and get a decent job whenever we need to. Most of us can trade Netflix for side projects and the costs of starting out are so low that there is virtually no risk.
Personally I would want to know because if came from a poor background his success story can potentially inspire many.
Privilege is a fuzzy term. A lot of people are born into good families but achieve way less than what he has achieved. So his background would not matter much for his achievements but it might matter a bit in giving other people hope just the way whether Tim Cook is gay matters very little for him but it matters a lot to little gay kids who want to be like Tim Cook.