Quote from Mudkip4321
I understand why you would want this, but it's pointless.
That's not a reason for them not to add it. Aesthetics should not be dismissed as useless, especially in a game where creating aesthetically-pleasing structures is a big part of the game's quality.
Red sand can't completely replace red sandstone because 1) it looks gritty like sand and not stripped like sandstone, and 2) just like regular sand, it's affected by gravity. Any stained clays look much too smooth for what I picture as red sandstone.