I don't know about subtext specifically, but I've grown a bit more skeptical about the possibilities of visual programming languages over the years.

As a game developer, I sometimes had to find ways to give non-programmers control of a system - allowing a level designer to control where and when new enemies spawn, a game designer to design the attack patterns of a specific boss, a sound designer to make his music match in-game events, an FX artist to trigger specific FX at certain times ... it's not easy to do right. We programmers sometimes make things that seem obvious and simple with little graphs with arrows and dependencies, but it turns out to be a headache for someone else to wrap his head around. What seems to work best is not making a fully programmable system (even if it's nice and visual), but rather defining a narrow set of operations that make sense for the behavior needed, and give a way of simply editing those; making something like a narrow minilanguage. And for that, simple linear text-based edition can work fine, without any graphical frills.

(Working with a visual tool works fine too, but it shouldn't become a full-blown programming language; give a level designer a powerful turing-complete node-based scripting system, and he'll make horribly complicated undebuggable rube goldberg machines, that could have been replaced by a few lines of code if he had explained to the right person what he needed)

Anyway, if you want to get better at programming, I don't think you should expect much from fancy new visual languages; it may be more efficient to get someone to teach you a bit.