You've generally gone for a very simplistic design, which you've improved slightly based on feedback. I quite like the mocks and I could imagine actually seeing it on TV. I particularly like your ITV News ending one:
While it is very simple, it actually looks really clean and fresh.
The wording still doesn't quite do it for me though on your mock, which it does work it doesn't really flow and comes across as a little oddly worded to me. Something as simple as "We're sorry, this programme is not currently available in HD." would suffice to me. Perhaps you could also add something like "You can continue to watch by switching to ITV" [and then giving the various channels for Freeview, Sky and Virgin].
It would be a 3/5 for me, it's 'Respectable' but it's easily done and not something that is too challenging or time-consuming to do which is why it wouldn't be any higher.
As a side point, of course, it's up to you what you post, but saying things like "That's it. I am so fed up." and "Those are all of what I, as a human after all, feels is the rude" seems a little counterproductive as a way to get people to give you feedback as to your work. While some comments can be harsh (and maybe rude at times), most people on here give it so that you can get lots of views and opinions of your work and you can then hopefully use it to improve your work in the future - we all learn through mistakes after all
I look forward to seeing any future mocks you do!