Why can't they write instructions

in English?
We invested in a new television set a couple of days ago. This was done reluctantly but the old refuses to accept the need to enter the digital age. We debated a set-top box but my BIL, who knows about these things, pointed out that there were problems.
Now it is not as if we watch a lot of television. My own television watching tends to be confined to a programme called Global Village (excellent short documentaries on SBS when there is no sport if you happen to live Downunder), the news on SBS and the headlines on the ABC. I have not been able to get the foreign language news services since they went to the digital signal but have been guilty of watching those in part if there has been a major incident and someone has alerted me to a story they are reporting. Once in a while I might watch a documentary. We debated whether we even needed a television set and decided "yes".
The reason for the "yes" was because my brother, who is technically minded and creative, makes short films for the family. These are not your average home movie/DVD but properly edited little gems with music tracks etc etc. My father treasures each one.
So, we invest in a new television set. My BIL sets it up and assures us that we now only need one little 'point and click' control device to do everything. Simple.
"But download a manual from the internet Cat," he tells me as he disappears.
I downloaded a manual from the internet and pass it to my father. He cannot read it. I look at it and do not blame him. It is full of abbreviations that mean nothing to him and very little to me. I guess that HD is "high definition" but HDMI? There is a lot of that sort of thing in there. I struggle through it but there is no information at all about how to play a DVD. I go back to the internet. I search. I find some information. It is not the information we need. We have the DVD in the player. I have brought it up on the screen but it will not play. My brother wonders if there is something wrong with the DVD. "Try it on the computer Cat."
My father watches his great-granddaughter on my computer instead but he cannot hear it because he needs his ear-phones for that.
Yesyerday I borrowed a DVD from the library so we could test the theory that it might be my brother's DVD. No. I can bring the picture up on the screen. I cannot move it on. Dad has given up in disgust. I have tried all the combinations I can think of. My BIL did it so I must be doing something wrong. I need to teach Dad so I have to get it straight - if only so he can view his great-grandchild on a decent sized screen with delicious baby sounds attached.
All I want to know is why they cannot write simple, straightforward instructions in English. Then I could read them.