You are forgetting what people had to cope with before. The new security popups are nothing compared to the abuse shareware has heaped on users.
If the security warnings are discouraging people from installing new software, they would equally discourage Chrome and Safari installation. So this is not an issue.
When it comes to web users, I lean towards them being "naive". You are free to hold a positive impression of the world as benchmarking enthusiasts :-)