I guess if you don't hear from them in a reasonable amount of time after an interview you're left to assume they aren't going to make you an offer.
This also happens in the sick-care industry. If you go for some test, they will only notify you if they can get more money from you, i.e. You've tested positive for some condition that they can "treat". Otherwise, if you're healthy, they'll just look at the test results, realise that they can't milk you for anything, and throw them out or file them without contacting you. Never mind that you actually PAID for the results that they never give to you...
Can you imagine being paid to create a web site (or anything) for someone, creating it, but never delivering it to them?
That is flat out rude - and becoming increasingly common.
Why is it rude?
Would you thank your toaster for nicely toasting your bread?
Would you inform your car that it's low on fuel and you'll be taking it to the gas station on your next trip?
Why do people feel entitled to not being treated like an object?
Why do people get offended when they are relegated to the status of a commodity?
What does being polite have to do with the bottom line?
Do stock holders care?
Does a company have any fiduciary duty other than to maximise profit?
Hopefully I've asked some uncomfortable questions.