PBP has a similar concept of hiding code behind its library of commands and also allowing you to roll your own
But isn't that what EVERY compiler does, ie hide the low level code from the user so he/she can write the code at the higher level? And isn't the difference in whether or not that "hidden" code is acceassible or not to the end user?

For example all the assembly macros that makes up a PBP statement is accessible, you can view them to determine exactly how a specific task is being performed/generated by the compiler and/or if the authours view of the world agrees with yours. I'm pretty sure the Arduino IDE's libraries are open as well, while the compilers from MikroElektronika all comes with "closed" libraries - I stand to be corrected though.

As for interrupts, PBP does have simple polled interrupt handling that may be quite insufficient if you compare it with other compilers for the same platform.
Very much so. ON INTERRUPT pretty much sucks. But DT-INTS gives you a lot of power and I'm not sure what MeLabs could do to improve on what we already have there. The upside is that we have a lot options depending on the application at hand. Sometimes ON INTERRUPT might be all that's needed.

I think most of us agrees on the limited string handling capabilities. It's popped up quite often, perhaps MeLabs is listening and working silently in the background. There's not been much (any?) development (released) on PBP for years now.