All that matters is that you have a numbering system and follow it consistently.
The python users will figure out what the numbers mean to them.
And I guess that 2.2 is not consistent. The changes from 1.5.2 to 2.0 seem to be closer to what happend with 2.1 to 2.2.
One measure of the oddness of 2.2 is the lack of 3rd party support.