So ... you're expecting them to log your searches for later analysis, or at least meta data about your searches.

That's what they promise to not do and the whole point behind many people's decision to use them.

And it might be obvious for some, but it still makes no sense :-) given the browser is capable of doing it.

well, this isn't something that I have given that much thought...

But yes, when I go to ddg and type in "!g <thing>" after having typed in "<thing>", I'm on some level hoping that this is somehow informing ddg that their search results for <thing> could be better.

Now, if they have somewhere stated that they are not going to do this, then yes, it would be bad.