Every whiskey-making culture makes both "straights" and "blends" except the Canadians. Each, in different ways, has followed a pattern in which blends are initially dominant, then are supplanted by straights. Actually, that's not true anywhere except the USA, but what has happened in Scotland and Ireland is similar, whereas although blends still sell more than "singles" (their equivalent of straights), singles are where the action is.
And yet there is a parallel phenomenon, of educated and experienced straights/singles drinkers revisiting blends.
What do they discover?
First, that blends are in fact another kind of whiskey and if you take them on their own terms, they indeed have something to offer.
Second, that blends may be a good way to introduce a friend to whiskey. People who contentedly sip Stagg have trouble accepting the fact that, for some people, Jim Beam is too strong.
Third, all whiskey makers intend their product to taste good. Nobody sets out to make a bad-tasting whiskey. Because blend makers are not limited by the restrictions that constrain straights/singles makers, it should be easier for them to make their products taste good and it shouldn't be a wonder that some of them succeed.
Fourth, what is a blend? In simple terms, a blend is a straight whiskey "diluted" with vodka. Mix your favorite bourbon 50/50 with your favorite vodka (unflavored, of course) and see what you get.
Fifth, the problem with taking blends seriously is that what you ultimately want to know about is the underlying whiskey, which brings you right back to straights/singles.