Why most apps try to use OSS if /dev/dsp is present?

So why most applications apparently try to use OSS if /dev/dsp is present on a system where more advanced audio servers (ALSA or PulseAudio) are also available?

I experience this after installing oss-compat on Debian Wheezy. Apparently for example the following apps seem to start using OSS no matter what else is available:

• MPlayer


• SDL (anything using the SDL library, such as Battle for Wesnoth)


• mpg321


• ogg123


• (third party) Firefox's (third party) Flash plugin

The reason for trying this is not quite relevant for the question, however check here if interested.

For me it would seem the more logical if applications (which are capable to use those) probed for the more advanced audio solutions first, and only tried to access OSS (/dev/dsp) when none is found.