I'm not really invested in this, but there are some things that are so much simpler to achieve in BASIC than in C, no matter how good the libraries are. The main one being string/text handling.
It took time to wrap my head around Arduino C/C++ (and it is much easier than C/C++ for operating systems), but I seriously miss those easy string functions.
I would love to see BASIC for Arduino etc. Whether I'd actually use it, on the other hand, is another question.
FWIW, I'm using the Arduino IDE for developing on AT Tiny85 up to the STM32F103 chips, so I need code that compiles down to very little at all (Tiny85) and a way to cram lots of twiddly bits into something more spacious (STM32). I'm not sure how well optimised any BASIC compiler would be with so many system options on te IDE.