People dislike line-drying their clothes out-of-doors because fabric conditioner smells better than fresh air?!?!
Yesterday one of the first loads this year of properly line-dried clothes came in smelling faintly of hyacinths. Real hyacinths, the ones that grow in my garden, not some artificial perfume synthesised from crude oil.
Soon the clothes will start smelling of tree-blossom, and after that they will smell of freshly-mown grass.
Fresh laundry smells so much nicer in the summer than in the winter, when it is tumbled or aired indoors.
Line-dried towels snap and flap in the breeze, and are softer than indoor-aired towels (granted, not as soft as tumbled). Line-dried shirts also snap and flap in the breeze, and therefore need much less ironing than when dried in any other way - including tumbling.
As for the rain, that's just an extra rinse! Unless you live in a town with heavy pollution, rainwater is cleaner, purer, softer, and better for your clothes and skin than tap water.