I've programmed in one dialect of BASIC or another for over 40 years and never had much trouble with the code. In fact, for parsing lines of text, it is still my go to (cough) language.
Certainly I've seen my share of spaghetti logic written by undisciplined programmers. We had taped to our wall at the software publishing firm I worked for, one egregious fragment as a warning to others that we had found in the code I was hired to clean up. (See http://www.rostenbach.com/programming_horror.gif)
But you can write structured code in BASIC if you do it right.
The problem are those that just want to hack out something and don't care what they are doing and you can find that in any language.
I used to work for a software publisher (Micro Lab) in the 80's and as I recall we had two tools, names forgotten, that would either take a file with symbolic labels and replace them with line numbers or we typically ran our code through a line number cruncher that would pack as many commands as possible to a line, while renumbering with an increment of 1. We did the crunching to make the code harder to edit by users and for performance.
Furthemore, I wrote a machine code library to hook into the Amersand hook to do disk I/O that was twice as fast as Apple's DOS command interpreter. The package was known as Language Plus, was poorly marketed and over priced to boot. The company insisted on selling it at $150, while I argued for $49.95.
We had other tools that I wrote that would print the listings one command per line. I liked drawing tiebars around If/Then and For/Next statements to analyze the code.
I worked at Wang Lab's while in school. My first exposure to Basis was on the Wang 2200 in late 72 or early 73.
Like others here I still use basic in VBA and Visual Basic. I find the old VB 6.0 still a whole lot nicer before it got microsoft'ed into its current form. Thankfully I still have some XP machines that keep it alive.
Remember Learning Basic on a Xerox Sigma 7 Mainframe in highschool -- The connection was via TTY to the state university over 300miles away -- The Sigma 7 was also used for the Navy's A-4 Skyhawk Simulators at the flight schools.
Never had the oportunity to do embedded basic, but did do embedded PLM code once, before moving on to assembler and C and later C++.
There likely still is embedded Basic code writen with that compiler flying today somewhere in the world--
Modern Basic versions like VBA, VBScript, and Visual Basic make it possible to quickly and easily transport code between Word, Access, Excel, windows batch files, and web server ASP scripts. Code modules I wrote in Word '97 in 1999 are still used every day in Word 2010 templates, Access, VB programs, and our Intranet site.
While I also had a trip down the (dark?) alley called APL, BASIC was the ticket to the micro world, thanks to the good folks at Parallax. From there, to the MicroEngineeringLabs PICBasic compiler, and then assembler and C (all pn PICs), it was a nice gentle introduction to microcontrollers. Yes, I had programmed Z80s in assembler, but BASIC brought me back to the embedded world.
I had a pretty good experience writing Applesoft BASIC. It didn't encourage writing great code, though. There were no labels, just line numbers. If you ran out of line numbers in one spot, you had to GOTO a differect section. (There was no real text editor and no cut-and-paste; one could only edit a line of code at a time, so renumbering code was too difficult.) There were a lot of GOTOs in general. I don't think you could pass variables to subroutines, so everything was global. Only the first two characters of variables were recognized. Comments were sparse because they ate up too much precious RAM. Anything requiring speed had to be written in assembly, POKEd in by the BASIC program, and called from there.