On the one hand, you have to seriously question the judgment of Lucasfilm if they repeatedly turned down this (mediocre, but not terrible) script, but eventually approved the garbage that Abrams wrote.
On the other hand, it seems likely that Abrams agreed to do the film on the condition that he be given complete creative freedom. Lucasfilm would have been in no position to negotiate.
So ultimately, like Solo, their desperate attempts at making a "better" movie ended up making the film worse. Just as the Lord/Miller version of Solo couldn't have been any worse creatively or financially than the version we got, so too did they make perfect the enemy of the good with Episode IX and end up with an inferior product.