One reason is plant palettes being burned into master plans. Another is availability. Another is cultural needs and growth cycles of some natives are different, and when they are planted, their needs aren't met they don't thrive and so get a bad reputation. And, natives can have pest problems, too. Every replacement tree has its pluses and minuses.
Oaks are subject to root rot and various insect pests.
Each of these species is a beautiful tree finely suited for the proper location and management situation. Management Options for Eucalyptus Even though dead trees provide valuable perch habitat for a variety of birds, they should be removed from most landscapes, as mentioned in the article, because of the safety hazard as well as our aesthetic sense. Decide the value of your trees to your property. List the trees, rating their level of infestation, likelihood of survival, and quality of branch structure. Wait and see.