The difference is that heat from a fire did not occur. High heat is requirement for most conifer seeds to release and germinate. The end result will be the regrowth of a different and most likely, deciduous forest or even conversion to chaparral. It also produces conditions that facilitate the large scale introduction of invasive species. This is the same sort of thing that happens with clear cutting without replanting.
There are a lot of areas where, if you don't then have a fire, you just get the stand taken over by other conifers. But, having a period where an area of forest is given over to deciduous trees isn't necessarily a negative, simply a difference. For me the main issue is not viewing the trees as a blight but rather a resource for different types of critters, and letting them stand unless you were going to harvest the tree from that area anyway. They are probably more valuable ecologically than healthy trees.
They do also make very striking wood products as well, though.