Not true at all if you bought a device that wasn't made by the big players (the majority of early media players). They had no DRM, and provided uniform, simple USB removable media access to the media on the device.
The record labels only stepped in when your quoted companies/brands entered the fray.
I think we're talking at cross-purposes about what we mean by 'No DRM'. The devices you're talking about would only run DRM free MP3s so in that respect they 'had no DRM', but they would be incapable of running DRM'd muic e.g. copied from a Zune or iPod.
But then Zunes and iPods could also always run DRM free MP3s copied from other sources as well, so I'm not sure what you think the difference was, or what advantage you think these independent players had with respect to DRM.
The record labels only stepped in when your quoted companies/brands entered the fray.