I think like every else it is personal preference.

It's more like a trend that is no popular at the moment similar to glass blocks just as an example.

Don't let trends scare you away from using something. If you like them and they work, go for it. Vertical blinds don't have to be metal, they can be wood, faux wood, even Hunter Douglas offers some great vertical options.

eztia, Vertical blinds answered the need for coverings that would work easily on the larger sized windows and sliding doors which became the rage in the 1950's and 60's. Big panels of glass were incorporated into office buildings by architects first and then they found their way into residential homes. Sliding doors especially needed some remedy to give home owners privacy and shade in ranch style houses. There's no right or wrong when it comes to what you select. Consult a professional designer for an hour or two for some alternatives or visit a retailer for ideas. You can combine different window shades within reason. Try to keep rooms that can be seen from one to another unified so that you don't wind up with too many lines to look at.

ez, I think the verticals are reminiscent of the 60’s and 70’s. There are so many other options now.