My take as a listener: It's obviously up to the station as to whether or not to issue a QSL. If the listener accurately provides the location of the receiver used, then the report is of value to the station for reception/propagation purposes. if the listener lies, well, the QSL should have no value to them.
In my case, while I will sometimes listen on a web radio to help determine what i am hearing (such as the Web SDR in .nl), I don't send reception reports for stations I've heard on a web radio. I understand the use of web radios to hear stations that are otherwise impossible at your location, but for me, the thrill is trying to pick up stations here at my location.