Good workmanship depends no more on the quality of the tools than it does on the way in which they are used, so to blame the tools for the bad workmanship is to attempt to excuse one’s own lack of skill.
Description:
A person who has done something badly will seek to lay the blame on their equipment rather than admit their own lack of skill.
something that you say when someone blames the objects they are using for their own mistakes 'This oven burns everything.' 'You know what they say, a bad workman blames his tools.'