I love that people think that removing a feature, which is built into a micro chip, would REDUCE cost.
Yes, it's about demand. Consumers wanted 3D for a while, so it was included on chip sets. For some reason people thought it increased the cost of the display because of this. Worse, it doesn't add to the cost of the display, but they removed the feature anyway.
Same is the case with Smart functionality and the rest. Some of the cheapest TVs out there come from TCL, yet the built-in Roku functionality is some of the best on the market. How much is the least expensive Roku (top tier quality product) - $30. It includes the case for the Roku, outputs, and a remote control to make it work. Probably a power supply as well. Remove the power, the case, the remote, and tuck it into a TV and what is the cost to add this? $10? $5?
It's just not a real cost addition when you get 10,000+ products into the market. Not when you lose half your sales if you fail to put it into the TV from the start.
Want to avoid it? You can get professional displays which don't have smart functionality. They also tend to NOT look as good, but hey, you may save a few bucks.
Try the LG 55UU340C. It's only about $800 online. What a deal (roll eyes).
In comparison, a 60" Hisense Roku TV is under $350 at Walmart.
It's not the 'smart' functionality that adds to the cost.