Why are there so many wooden box speakers out there?

Hello Kenjit.  Wooden box speakers are traditional, easy to pack and ship, easy to place in a home (flat bottoms), easy to put things on (flat tops), easy to mount speakers (the actual drivers + crossover parts) in (flat fronts and backs), easy to "tune," easy to build. If you build it with stone slabs (counter tops broken during fabrication are available cheap. The shop can cut the pieces and holes for you.) you will have and acoustically inert box that will not sound "boxy," and can look quite impressive. Glue it together with silicone rubber. Open baffel speakers are lighter and cheaper (especially DIY) to build, but harder to place in a room. Happy Listening!

I'm the first person to agree that savvy marketing and the canny wooing of the right review journals can have an enormous and sometimes deleterious effect on consumer choice; that people more often than not want what they're told to want whether it's good for them or not. But in this case I think you have to be a bit realistic. 

We--by which I mean people on this forum--are a minority who will sometimes go to absurd lengths, both financial and aesthetic, in pursuit of audio perfection. Most people want something that sounds nice and looks good, and the simple fact is that wood looks nice and rectangular shapes tend to fit better into people's living rooms. Here, I think, is a case of manufacturer's giving people what they want, not, as the OP suggests, duping them.

I should, however, declare an interest. My Sonus Faber speakers look fabulous and have just reached the point after about eight months of hitting a perfect and exquisite synergy with the rest of my system; plus my wife thinks they're really pretty--a not inconsequential consideration for those of us who do not possess dedicated listening rooms to which we can retreat!

I’m going off topic here, but rounded shapes are preferable for living room decor. You’ll get very subtle anxiety in a room with only square shapes. It’s soothing to the mind and spirit to have more rounded shapes that you’ll likely encounter in nature.

It’s fine to have a few hard edges here and there, but you can break up the pattern with decor: pillows, candles, vessels, mirrors, plants, tables, plates, lamps, chairs etc...

I doubt that the square shape of a speaker is inherently desirable, it’s just practical.

I am so confused. A square is also a rectangle so how can a rectangle sound better than itself?

Why would any competent person use wood for anything let alone to build a box with! it's just a horrible mistake! I'm glad you pointed this out to us. I'll now get rid of all my wood.