Humans are really good at throwing environmental pressure (logging) after environmental pressure (chestnut blight) after environmental pressure (urban air pollution) after environmental pressure (global warming) at species. The speed with which these pressures arise is faster than natural selection can deal with for most species, and are leading to an extinction event rather than species just learning to adapt. If we can make minor direct genetic modifications to help species cope, I think it's an unqualified win.
Stripped of that, it says "the new gene will be in the tree's the gene pool forever, so it's a bad idea" which is a non-sequitur. Putting the gene in permanently, for permanent fungus resistance, is the point, isn't it?
The emotional appeal is the entire argument. It seems to imply that gene editing is always "bad and dirty". There might be a case to be made that putting this particular gene in this tree is a bad idea, but this sentence is really not it (1). I think that I had an emotional reaction against it ;)
IMHO Gene editing is too broad a category to judge like that. Comments on the internet - good, bad or useless? It depends on what you write, and where.
If someone is going to ask for "comment with evidence", then do not reverse the burden of proof (1) and put that on "downvoters", instead ask for "sources" that all gene editing is "contamination", rather than giving a free pass to sneaking in the conclusion via loaded language, without supporting evidence.
I think that I gave this topic more in-depth examination than it deserved, but there you go.
1) https://en.wikipedia.org/wiki/Argument_from_fallacy
2) https://en.wikipedia.org/wiki/Burden_of_proof_(philosophy)
1) resistance genes are already in the genome, they don't need to be added. This means the entire endeavor is unnecessary
2) this is an internationally recognized definition of genetic pollution, it's controversial only with a few hardliners.
2. If you read the wikipedia article [1], it has an entire section on why it's controversial. It also has links to an article on genetic rescue[2], which I think is more relevant.
[1] https://en.wikipedia.org/wiki/Genetic_pollution#Controversy