Bad design insults me as a caring older brother
When ever I wonder why interaction design interests me, I need look no further than at my kid brother (who's seventeen) use the computer. Seeing him strugle with badly designed sites and programs makes me determined to do something to help them, and even a bit angry at the inapt developers responsible.
I've witnessed countless situations, involving said "test subject", where I kept thinking: "What would he had done without my help?" I shudder at the thought of him getting turned off from using this wonderful medium to be creative - as he currently is, doing video editing - because of design failures.
We've certainly come a long way since early days in term of user-friendliness (excuse the cliché), but to think we're there - or even close - would be a grave injustice to people like that brother of mine.