MATLAB actually had a lot of changes over they years that broke working code (e.g. changing the order of function arguments and outputs). It is by no means more stable than Python (2 or 3).
When ruby broke all applications when changed from 1.8 to 1.9 (note that it also was a minor version change) no one complained, they just fixed their language and moved on.
I think Python spoiled developers.
There would be less issues if it would never released 2.7 (that version almost exclusively was backporting 3.x features - until 2015 people were asking what features 3 would give that 2.7 didn't have) and just deprecate 2.6 after a year or so like everyone else does.
