What do you mean with that term?
Several brands ID any material with a soft hand as a soft shell. If you take that soft hand fabric, put a water resistant / windproof layer in it (a three-layer fabric), you have essentially created the utility and characteristics of a hardshell.
Take what Steve at Coudveil was after (who now owns Stio).... a wind resustant, water resistant fabric with a high degree of breathability for missions in the dry, Intermountain West. Schoeller had a fabric that they used on high-end upholstery. Steve adopted it for outerwear, and created a new channel for Schoeller. Much like Peter and Patty Duke created Smartwool, and created the Merino market for mass consumption (and they now own Point6).
The diwnside? Engineering and creating that fabric to exhibit the above characteristics through its physical properties is not inexpensive. In many ways, a three-layer "softshell" is a way for brands to play in the softshell arena, while reducing retail, increasing margins, or both.