Because some help desk told them to. The other day chase manhattan was down with a full on 500 server fucked up. Their twitter account responded to me telling me to clear my cache and delete my cookies. Classic.
A naive user would then open settings in an emotional and annoyed state and would turn off anything that caused an emotional response of fear. JavaScript, Ive heard of that and I don't like it so kill it stupid thing computers are so frustrating they never work. Click
Why would scared people even open the settings dialog?