Here are the DVD and Blu Ray sales over the years in the UK.  As you can see,  dvd was huge and is still big.  Bluray was never that big. UHD as you can imagine is tiny and like Bluray never became big neither will it. 

Number of discs sold in the UK, by format and year

DVD
1998 0.2m
1999 4.0m
2000 16.6m
2001 41.3m
2002 89.9m
2003 145.0m
2004 196.5m
2005 211.2m
2006 227.0m
2007 248.1m
2008 252.9m
2009 234.6m
2010 210.1m
2011 191.8m
2012 162.0m
2013 143.4m
2014 124.9m

Blu-ray
2007 0.8m
2008 3.7m
2009 8.4m
2010 13.0m
2011 15.3m
2012 16.7m
2013 18.8m
2014 17.3m

Don't care about any of this BS lol. Does it play games? Yes? Ok thats good enough for me.

It doesn't matter how many discs are sold.

Adding a 4k Blu-Ray drive adds very little to none to the systems cost but is a very good check-list feature for some.
Plus it's not the only Disc format the PS4 is unable to run, CD support is also non-existent.

Besides, one day you might end up with a sizable 4k blu-ray collection picked up from a garage sale or swap meet. Would be nice if all your hardware could run it, correct?

UHD Bluray isn't very relevant, but its gonna stick around.

4K TV userbase is growing, X1 is already using UHD Bluray, PS5 will almost inevitably use it, so games will eventually be on UHD discs.

Right, this thread is really in defense of Playstation not using it. But its new and superior tech that adds little cost per console. If you have a 4K TV its the best picture quality for movies, which is great for devices focused on 4K!

As I just mentioned, its inevitably going to be used for gaming because its a cheap and holds a lot more storage than discs currently used.

Many people don't exactly buy Bluray discs. But they seem to be really popular rental kiosks. Where I live there is a Redbox often blocks away from each other or even across the street. That's impressive considering physical movies are apparently dead.

sure it won't make the xbox one S a better sold console then the PS4, but you have to look at how little the costs are to include a UHD and then realize its nicer to just include it.

But yes, it will just be a few thousand people who buy it just for the UHD-feature and most people won't care.

Within the context of this thread, and the point he's trying to make, it completely matters how well physical formats are doing and the historic precedent we have is a great tool for gauging the importance of ultra high def. would you be singing the same tune of UHD sold less than a million discs per year?

Ultimately I agree that Sony should have included UHD. But unless we see game installs or day 1 patches disappear from the xb1S using an UHD drive, it doesn't affect the key component to a console - gaming. 

Is this a PS4P defense thread? Because it feels like one. I'm going to be working on a 4K Bluray collection because I got a player that can do it. Same way I build up a DVD collection because of PS2.

Though physical (including rental) is still in a steady decline, while digital is also steadily increasing.

Look at that growth in DVD sales after the PS2 Launched in the UK (2001) it's crazy, also crazy is the fact that if you combine all the years sales of Blu Ray discs... it doesn't add up to any year after 2002s sales of DVD's they just really never caught on the same, sure you can tell somebody that it's super dee dooper HD, but really most people probably have youtube and their streaming services set to Auto and just enjoy their media at that resolution.

Considering that by 2014 it would appear that Blu Ray was already on decline then it really is hard to justify the inclusion of the player on a console, I mean... sure it is a nice feature if people would use it... but realistically that just isn't the case, would be like saying that for another $20 they could add a VHS player to the PS4Pro, like... it's a nice feature but the same number of people would probably make use of it.

As for the thought that games for the X1 would come out on UHD discs, keep in mind that this would render them incompatible with the original X1 models, which wouldn't really be a great idea nor would it be in line with the vision of a generationless console that is the Xbox 1.