I find the pirates are too easy . Ive noticed on some random maps your homeworld can only have 1 way in and out and that 1 way can be a pirate system - that can cause the AI to get stuck and not leave their homeword - thats the ONLY reason i can see for making pirates weaker.
If your having trouble with pirates then try playing with them off - or perhaps try and bounty the AI before they bounty you
or else turn the pirates off.... - id like the pirates to have phase jump inhibiters and i like the idea of them having starbaees with enforced loyalty to prevent TEC from bombing them-
Late game pirates need to be a threat - they should get a titan somehow or ateleast start getting a level 4 cap ships when 10k is spent on bounty