You do have a point. But I think you underestimate the power of knowing "who is asking the question". Take the search term "String" for example, the one searching might refer to "String" in (1) programming, (2) physics, (3) music, (4) clothing ... the list goes on. Let's say you know the one searching refers to (1), even here you will be better off, knowing if the one searching wants to know about the string class in Java, C++, C# or whatever..
This might be a bad example, but you get the idea. The better you know the one searching the better results you will be able to provide.
It is easy to add this information in the search – in the particular example, adding ‘Java’ will likely mean that someone is not looking for specific strings from a tropical island or the local clothing types, but your ‘type 1’ strings. Even better, the same person can look for clothing by adding an appropriate identifier, without having to worry that ‘type 1’ answers leak into their ‘type 4’ query.
This might be a bad example, but you get the idea. The better you know the one searching the better results you will be able to provide.