A lot of their music is extremely mellow, I like the harder stuff like "Roadhouse Blues", great stoner music, but a lot of it could actually, be played in a nursing home. I know Doors' music very well, like "The soft Parade" is soft. I know Morrison was not intending to be soft.
Skynyrd did some soft stuff like, "The ballad of Curtis Loew", even GNR did a couple of elevator tunes, the Who as well.
There is no band like the Doors, but a 75 year old Granny could easily like "Touch me" and more of their stuff, lots of Morrison stuff is soft.