With so many clamouring to get their music heard these days, any convenience you can afford the listener is important.
In the songs forum, it's quite right that some would refuse a download as it slows down the process of reviewing greatly, it could take 50 minutes for example for some to review 10 songs that way. You either have a fast connection or you don't review many songs is all I conclude from you even bringing this subject up.
If you wanna be heard then accomodate the listener, rather than try to educate them.
If you use your own streaming media player server side you can even govern the quality and format of your uploads.