I consider myself a hardcore boardgamer. I play the most complex games with ease and don't mind the long game time or the complexity (well maybe not to the extend to something like The Campaign for North Africa). Many of the games in my collection are classified medium-heavy or heavy.
Most of those games require a lot of time just for preparations. It can take a hour before you can even play a single turn. Often the complexity is with the setup and initial understanding of the rules. Once those are set it's easier for others to jump in. Just takes another hour to explain the game and rules to them.
I like those games, but sometimes it's nice to just sit on the table and start playing. The heavier games can give a lot of strategic depth along an immersive story, but the games that take 5 minutes to setup and explain can be as enjoyable and challenging.
I'm pretty sure it's a lot easier to design a complex game than it is to make a simple game that can still be engaging and offer replayability. There is a place and time for all sort of games. I'm happy that despite the bias to more heavy games I do have a wide variety of games of different complexity.