"Qualitatively" UI work is far more useful to society.
My senior thesis was a receipt printer that wireshark'd instant messenger messages on our school's unsecured wifi and dumped those messages into a pile.
As for your senior thesis - Developer's job is to create software that makes lives easier. It was your decision to use your skills to harm people by exploiting their privacy. Or it could be seen as something good - you discovered a way to exploit people and if you informed whoever was running this app you helped a good amount of people in your school.
It takes critical time and energy to reduce the complexity of a products' features to something a layperson can use, and a layperson is usually barely paying attention.
As to your second point, I wasn't a developer, I was an artist, attempting to ask real questions about privacy and spark real discussions and possibly getting myself in trouble to start a conversation.
Only half rhetorical, as I'm actually curious.