Heh, I can see how a full Windsor could be reminiscent of '70s fashions... and not in a good way. Like thescot said, I would imagine this is a function of the material. I have some wool ties (as well as other woven ties in similar thicknesses) that would look awful with a Windsor knot. I only use the full Windsor when I have a relatively thin silk tie that I can still get a nice, tidy, triangular knot in. Fortunately, that's the majority of my ties.

A tightly-tied Windsor can look just about the same as a medium-tight half-Windsor, with the added benefit of using up a little more material so the length isn't an issue for me. Plus, with a nice tight knot, it makes it easier to pull the 'dimple' just under the knot when I finish it up. I'm very meticulous about the dimple!