Built-in BASIC = cool, you say? Damn you!
I've wasted countless hours in my life typing BASIC, only to achieve modest results. If only a more powerful language had been included in those machines... Say Forth, or C, or Lisp, or <insert structured-language-of-choice here>. Had any such language been built into popular machines of the day, science and technology would have advanced so much faster that every citizen on this planet would have had his/her own flying car and faster-than-light spaceship by now. But no... BASIC.
I've made many attempts to bring a logical structure into my BASIC programs. To number lines in steps of 10, in order to insert lines as needed. To reserve a range of line numbers for sub-routines. Only to find out that for programming, line numbers AREN'T NEEDED IN THE FIRST PLACE. Or editing - using a "LIST" command to show a few lines, move cursor to one, edit a copy of it elsewhere on screen, and have it inserted back in. Only to find out later that editing text is easily done full-screen. Yes... BASIC.
Then I found out about machine code. It was like being in coder's heaven, being God of the machine, but very difficult because it was like inching forward with tiny, dangerous steps on a minefield all the f**king time. Knowing that you'd still need that BASIC interpreter to get running, and that the same BASIC interpreter would often get in the way, and eat globs of precious RAM even though you weren't using it anymore. And that no assembler was built in, because there wasn't any room left in the ROM after putting BASIC in there. Grrr.... BASIC.
And let's not get started about the days of Disk Operating Systems. Cryptic commands to do even the simplest of tasks, that low-and-behold actually made a machine somewhat useful.
And to add insult to injury, it turned out that even for low-spec-machine-I-was-stuck-with-because-dad-couldn't-afford-anything-better, many of those more powerful languages were actually available! Some even for free! So manufacturers could have built them into their machines! But no.... BASIC.