No, nothing to do with jpeg compression, they are just blurry. First screenshot shows you clearly the clouds in the foreground left and the little patch of clouds on the right. I can see it in all of those pics but the first pic should be obvious to everyone.
Yes, the promo stuff looks fine but what you don't see is all the flaws when you will actually be using the sim and say flying low and slow from one airstrip to another. That will almost certainly tell a very different tale.
Then will come performance. System needed and how all this scenery will draw. From what has been shown so far popping, stutters and although I haven't seen it in the promo stuff yet, blurries I am certain will also be an issue.
Like I said, wait till release, till people are actually running it and then you will start seeing real evaluation of the product.
Then of course are things like lack of seasons and all the other features that won't be there from FS2004 or FSX.
Then on top of that, let's see costs, storage requirements, bandwidth requirements.
I know I sound highly negative but I game a lot! Despite what people say, FS is just a game and things won't be any different for MSFS as they are for any other game. It uses hardware the same, it lives in the same market and times.
What's clear, there are many things of concern and as of yet MS have released nothing to remove these concerns which in itself is a typical modern day tact and worrying.
I'd be happy to flip to a new sim as well but I don't think MSFS is it.