Nope. See http://en.wikipedia.org/wiki/Smalltalk
Sure Lisp doesn't use commas. Parenthesis can be made optional in Lisp too. Therefore semicolons, colons, commas and parenthesis are all equally optional. Woohoo! No pesky syntax!
There are some differences between making commas optional and making trailing colons optional.
"There are some differences between making X optional and making Y optional" for all features X and Y.
Clearly the use of the specific semicolon character is confusing you. So let's replace it with a better symbol: \n as in this example:
for i in x: foo(i) \n bar(i+1)
Sure a \n is optional at the end of any line because a blank line is always allowed. So what?