Improve some minor phrasing.

Author: ZeroIntensity

peps/pep-0788.rst

@@ -891,7 +891,7 @@ However, this ended up making the proposal significantly more complex and
 hurt the proposal's goals:
 
 - Most importantly, non-daemon thread states place too much emphasis on daemon
-  threads as the problem, which undermines the PEP's clarity. Additionally,
+  threads as the problem, which made the PEP confusing. Additionally,
   the phrase “non-daemon” added extra confusion, because non-daemon Python
   threads are explicitly joined. In contrast, a non-daemon C thread is only
   waited on until it destroys its guard.