I'm in compilers and programming languages. I really wanted to create my own language as part of my PhD thesis, but I was basically told that this would be unpublishable. I mean, how can you hope to numerically show that your language is better than everything else around? Plus it's all been done already, nothing else new can possibly be invented in that realm.
Things weren't always like this. In the 1970s, we created things like Smalltalk, ML and LISP, which had a tremendous impact on the programming world. People also had bold ideas about artificial intelligence and nuclear-powered spaceships. In the 70s, people were allowed to just explore ideas, in the hopes that these ideas would lead to something good (and some did). Now, it's much harder, you bring up an idea and people immediately try to shoot it down, ask you for proof that it definitely will work, and bring up the most asinine suggestions as to why your idea will definitely fail.
Today, the exploration has been scaled down. It's not because the exploration failed, we invented many great things as a result of it, it's largely IMO because we live in different economic times. The USA is no longer in an economic boom, things are no longer in expansion. There are cuts to scientific funding, cuts to education. People are being told not to be "wasteful". We live in a much more nearsighted world, in a sense. Being a dreamer isn't considered a virtue.