The main problem I have with it is in many cases the upstream data has to be available to a node in order to be allowed to open the node up and see the configuration. This has resulted in my spending a day or two updating and tweaking database queries on an old connection and fixing the resulting configuration errors just to get to one node and read the configuration. In this case I didn't care about the data itself, I just needed the config of that one node.
This would not have been necessary with a text-based tool, where I could just scroll down and read. Knime can be a powerful tool but for sharing work I think it's unnecessarily painful.
You also have Orange from Biolab, although is way less powerful but it has some cool nodes and AFAIK it was possible to open up nodes config without connecting them to anything.
Also, Knime and similar apps show a workflow way easier to understand at first sight. Specially for people with low programming skills.
Not to mention that you don't have to care about the environment and quirks of the packages and so on, although I recognize this is not really a problem in R, but I had with Python from my noob perspective of programming.
I do pretty complicated stuff with Knime, PostgreSQL and Apache Nifi. I make workflows almost on the fly, snap many operations to them, etc. I'd love to see this guys doing something similar in the same timeframe I do.
Well made GUIs like Knime has, make your life easier, this kind of articles sound a bit snob tbh. This statements are true for developing websites and many other fields, not really for treating data. It doesn't make much difference given the current tools.
Edit: I see people arguing Excel is fantastic. It's true, it's amazing but it doesn't keep track of what you do with the data. It's difficult to understand what's going on if there's something even a bit complicated, not to mention if people just copies and pastes stuff everywhere, which is common.
Sorry for my poor english.