Limit is much more than that, attached pic has 80 characters. I don't know what the limit is, Adrian indicated probably just screen layout.
You are showing a 16:9 screen, yes, it is wider than the standard 4:3 720 pixels that the 32 character limit was imposed.
Higher res, wider screen will fit more on the line, but what happens to the subtitle when viewed on a SD 4:3 TV?
Do you remember the early days of computers when the screen was 640x480? The max characters you could clearly see was 32. There were 80 character screens, but the text was hard to read.
Carl312: Windows 10 64-bit 8 GB RAM,AMD Phenom II X4 965 3.4 GHz,ATI Radeon HD 5770 1GB,240GB SSD,two 1TB HDs.