4K UHD: Fewer subtitles than on regular Blu-ray? Why?

[Fjodor2000]

Hi,

Based on my observations, it seems like 4K UHD Blu-ray releases often have subtitles in fewer languages than regular Blu-ray releases. Some even don't have regular English subtitles, instead only English SDH or none at all.

Now I just wonder if there is any logic to this? If anything the UHD Blu-rays ought to have room for more subtitles.

Personally, I find this highly annoying. It has put me off buying several UHD Blu-ray releases.

So is there any logic to this? Not having a wide selection of subtitles on the UHD Blu-ray discs likely means less sales in a lot of countries. Is it really that expensive to add more subtitles? Why not just add the subtitles from the existing Blu-ray discs to the UHD Blu-ray discs? Is that more expensive than the effect of having less UHD Blu-rays sold in a lot of countries? Seems strange to me.