The Pascal community fragmented. The 8-bit systems carried on using ISO Pascal or UCSD Pascal, but Wirth and other key Pascal experts went off and created Modula-2, which was much more practical for real world programming. (I used Modula-2 on the Atari ST, it was a much nicer experience than trying to program GEM in C.)
But instead of Pascal or Modula-2, Borland went off and did their own thing, producing a proprietary "Pascal" that wasn't compatible with anyone else.
Then the Modula-2 community split into the Oberon (Wirth) and Modula-3 (everyone else) communities to add OO, and Borland again did their own thing and ignored everyone else.
Now we have Go, which takes C and adds in ideas from Modula and Oberon. And Free Pascal still isn't even compatible with 1982's standard ISO Pascal.