The answer would be things like last 5 deposits and similar situations like you see on banking sites. Many of these are predetermined queries and people want to simplify as much as they can so to support TOP and get a correct result ORDER BY was allowed under this situation from my understanding, it isn't the other way around. Without order by then TOP would be in many many cases useless when you give a fixed range. There are arguements for this both ways of course and over a period of time TOP was built into views and ORDER BY was added to only support that situation.

In reality a vendor could design ORDER BY to work without the TOP cluase which woul be against the standards but they could and if they saw more users adopt them for this feature then others would adopt and thus would the standard be change eventually. The customer still drives the market and standards can be changed by this drive.