Absolutely wrong!!!
The correct way is to test as you say with real world scenarios but the testing should be performed by professional testers with the site inaccessible to others, then when fit for purpose, released as Beta allowing approved users on.
Professional testers will ask real world questions, if they're good at the job - I certainly did!
Your suggestion is what Microsoft appears to do, relying on the end users to do their bug finding instead of producing a finished product on day one hence the constant flow of updates to Windows.