Do they really need to fix this? I don't see what is wrong with putting text in number-only inputs. You could already put the join block inside any number-only inputs to put text in it.
Perhaps one could even say “it’s not bug … it’s a feature”. From what I’ve understood, part of Snap! ‘s philosophy is making it easy to do what most users want to achieve most of the times, but if a user consciously chooses to circumvent gates and climb over fences, that’s totally OK.
I mean, you can type text into the number input in the item of block, and dropdowns allow for text in number inputs. If they removed the ability to put text in number inputs, the existing scripts that utilize that feature would be broken.