Re: I don't want a smart TV.
> Why on earth they don't have a similar arrangement to the CAM sockets ...
0) Physical space.
1) More expensive (connectors, additional casings).
2) (Most) People don't care.
3) The 'sales' people at Currys are the primary channel for communicating product information (don't make your product the one that is hard to explain)...
4) If you have different platforms that confuses the picture for content partners you are bringing on board and you want to maximise the number of viewers that can be reached.
5) Stock control. We have 1500 more processor modules left than TVs to put them in (or vice versa).
6) Internally the product changes every year to bring the costs down.
7) Additional failure point (especially the connection)
I believe some high end Samsungs offered an upgradeable module but I didn't follow it closely. It really isn't a cost effective approach.
Depending on what you want to do you can do it yourself with a Rasberry Pi powered by the USB and plugged into the HDMI or a real computer powered by the mains and plugged into the HDMI. Use HDMI CEC for the control and you can use the original remote. Most people will stick to the built in services (and DLNA) if they connect to the network at all.
> It's essentially how these things are manufactured anyway...it's the same screen in Bravias and Samsung TVs, it's just the electronics generating the picture (i.e. the "Bravia engine") that differs.
Not entirely. Yes the main board is the same or nearly the same +- satellite tuner and at the top end extra picture processing hardware but the panel also varies (particularly high frame rate support + 3D and possibly backlight technology or bit depth).