The greater vision
The greater vision is that all computers run a client-side program, potentially embedded in the operating system, that measures the cryptographic hash of all programs and content being downloaded to the computer. Before the program is run or the content loaded, the hash is sent to a global database on the Internet for analysis. The database has a list of programs and content, as well as their related cryptography hashes. Additionally, each registered program has been ranked by security professionals as to the program's security, privacy, and operational methodology. There can be several main categories, each with varying levels of trust, that developers work with. Think of it as kind of like Common Criteria, but with a broader scope.
The idea is that the global database can act as each end-user's personal security advisor and recommend a go or no-go decision. A simple end-user message might say, "This program has been found to collect personal identifiable information, redirect Internet browser searches to paid locations, make potentially malicious modifications to your computer system, and send collected information over outbound network connections to multiple servers. Its legitimate intent cannot be confirmed. Most users have chosen not to install."
Another program, having the exact same behavior, might come from a trusted vendor and be recommended for installation. But at least the end-user would know that the program modifies their system in readily transparent ways. This might encourage legitimate vendors from slipping in "phone home" features without making users aware of why they're doing it.
Media content can be verified not to have known backdoors, malicious scripting, or other unexpected consequences. By default, unregistered programs and content would not run, or they would be subjected to additional scrutiny and controls (for example, sandboxing). Many programs are digitally signed today, but users still don't know what they do.
It is unrealistic for most end-users to be as knowledgeable as a 20-year computer security expert. So doesn't it make sense for us to help innocent end-users, who just want to do their jobs and have a little fun with their computers, make informed decisions?
Because ultimately, we don't want to stop end-users from installing and running any programs they want -- just the bad ones.