Hardly. Volunteer positions come with responsibilities. No one is forcing them to waste their time on moderating an internet forum, but they chose to do it for whatever reason and then chose to be lazy and actively harmful.
The complaint here is about moderation tactic that is not actively harmful or abusive to people and ease their own load when threads become too much. Complaining about that is absurd.
No. The purpose of a subreddit is to let users engage. Excessive locking decreases user engagement and is harmful, not to mention that it punishes users (who are no longer able to continue a already started conversation in the comments) for violations of others.
