Fix what?
The web is an open platform. It's not up to Apple to police it.
Actually, Apple are being very naughty.
Type the following URL into Safari, and you will see the iTunes application start up.
itunes://
What's very wrong with this is that 'itunes' is not a standard web protocol, unlike http, ftp, file, https etc. If Safari played ball properly, an address like the above should not be resolved. Type sdcsdckjnksdcn:// into Chrome, for example, and it won't complain that no application is set to respond to a URL of that form. It will do a search instead.
By contrast, requesting some kind of
resource via a URL, be that an image file, a movie, a spreadsheet or whatever, provides the browser with a hint as to how the file should be opened, and that can/should happen automatically.
Apple are on the naughty step here.