Why minimize WIP? Because WIP holds the risk that you're building the wrong thing. In manufacturing this might be using flawed parts that won't get tested until later in the process or it might be building inventory that you ultimately can't sell because the market demand has changed. In software WIP risk could be a misaligned understanding of the requirements; a flawed view of what minimum viable product looks like to the target market or a technology stack decision that represents a performance dead-end. In all of these examples you want to find out if you've made an error as soon as possible because if you're wrong then all of the WIP may need to be discarded.
A smart team holding to the core lean principles should feel empowered. Arguably Scrum, in it's dis-empowering form, is just another process to help manage mediocre teams.