I'm not gonna lie; I pretty much skimmed through this post. However, I read and took enough that I can wholeheartedly agree with your statement. All of us hackers had that full scale dream when we started, and as you stated, rarely have those dreams come to fruition.
Just like you, I can point right at myself. In order to get something grand to be completed, a serious amount of planning needs to be done. I got through 16 chapters of the first version of Devourer of Worlds completed when I decided I didn't like how the story went. Then I started over... and then again... and then again until I am where I am now (which is no where lol).
As a teacher, I understand that it is difficult to go straight to the big things right off the bat. Rarely can we do something grand on the first try. One way I like to teach concepts is by chunking a problem into smaller pieces or steps. Instead of mastering the entire thing at once, break the whole into pieces and master each piece, and then put it all together later. This strategy may not really apply to hacking though, but I'm sure most can catch my drift.
I left the fandom pretty much three years ago. There were no complete full scale hacks. I come back, and it doesn't look like we have progressed much further unfortunately. I do believe, however, if this small scale approach was taken, then my statement would not hold true.