Well, lets see. You said that Lee devised a plan of battle for the Seven Days that was "horribly executed". You also said that Lee's "failed invasion" of Pennsylvania was a "disaster for the Confederacy".
I'd say we're in total agreement. Lee was a great strategic planner, but he sucked as a tactical commander.
Lee's failure in any given battle seems to be preceeded by some instance of gross incompetence among his subordinates sabotaging the overall battle plan.
If Lee wished to blame subordinates for his own shortcomings, so be it. Others however, would point out that Lee's inability to adjust his battle plans accordingly was one of his biggest flaws as a tactical commander.
Cheers.
Inability or unwillingness, I'm not sure it mattered. The man was stubbornly insistent that the plan was good. There seems to be a consensus that the South was defeated by their backward economy and lack of resources/men, rather than the incompetence of the high command. There are examples of poor leaders, but Lee should not be placed among them.