Many regattas do use triangle and B mark courses--last weekend our RC sent us around the B mark on 3 of 5 races.

One of my favorite regatta locales actually does have some pretty complex courses around its "permanent" buoys. See: http://www.fresnoyachtclub.org/data/Club%20Races/Huntington%20FYC%20Club%20Race%20Sheet%202007.pdf

So, the reach is alive and well. Personally, I think the most tactically interesting courses use short reaching legs to break up otherwise long downwind stints, such at course #7 on the above linked map.