A lot of it is to do with quality and by that i mean picture quality. Everything is in HD or 3D now and since we didn't grow up with this then it still seems strange to our eyes/mind. The HD and 3D generation will grow up with this being the norm, they'll look back on most of the old films and think they look crap, obviously there are exceptions. Everything is shot on green screen now a days, that's why Inception was such an amazing film because the amount that was actually filmed on location is incredible but again there are exceptions. One comment i saw about Gravity was just amazing, it's not word for word but it went something like......"really disappointed with the amount of VFX in Gravity"...... Yup me too mate, don't know why they didn't just go into space and film that huge disaster. These sorts of people shouldn't be allowed to watch films full stop!
Another issue is that it seems like any script will get funding, how people can honestly think some of these films are a good idea is mental and most of them, in my eyes, are remakes. Again this goes back to picture quality and ease for people, which would be the only reason would be recreate something like The Thing or Let the Right One in. Let the Right One in is an incredible film but many people would be put off by the sub titles and those same people are probably put off by watching a dubbed film, so what do you do? Remake it! (you should just watch the subtitles but people are idiots)
I do believe that the quality of scripts has gone down but only because it's too easy for people to get films out there, so what we see is maybe 1 in 10 quality scripts, where as it used to be maybe 1 in 3. The fact that films try and cover for a shite script by slapping VFX all over it is fine by me because it keeps me in a job but then for something like Gravity which was a first for any film being shot like that. People say the script for Gravity was shite and yeah it might not have been the best but it was 1 single actor for most the film, the whole point around it was to bring something new to the table, which thankfully a lot of people noticed and praised the film because of it. It's rare to have a film like this though and the amount of crap that gets made is pretty awful.
You also could say that there were just as many crap film made back in the day it's just we only watch the good one's because of what we've been told, where as now i think a lot of people ignore critics and will watch something no matter what someone says.
Sorry kinda rushed that at the end because of work, i might come back and write more.....also haven't had a chance to read through it again so sorry for any spelling/grammer mistakes