At the beginning, problem with dugouts was that people were using them as throwaway vessels and throwaway bridges for hearthlings. Seems that dugouts aren't affected by quality of log as well. Main problem is 20 minutes waiting period for those to be usable.
Since I don't wanna waste dev team time on taking a step back in this matter, here's a simple solution everyone should like and make dugouts better than they are now and is a somekind step further.
Unburned dugout: can be used as it was used before, but animals break them two times faster than burned ones. Heavy. Slower. Decays a lot faster. Maybe visibly faster.
Burnt out dugout: A bit lighter, so hearthling moves faster, is a tiny bit faster than unburned dugout and decays a bit slower.
TL;DR: bring back insta dugouts, but burnt dugouts are superior to them.