Fr. Rose is an interesting person: he started from what was possibly a very bad version of fundamentalist Protestantism (if it resembles the views of this book) to become sort of a perennialist and a reader of Guenon. He later correctly understood some of the problems of this perspective and embraced apostolic Christianity through the Orthodox church.
The problem with this work is the same of the other works of Fr. Rose: an incredibly narrow form of Orthodox exclusivism, to the point of almost considering heretics most of the people inside this same church.
Like in his other works, an exceptional and rigorous clarity in identifying problems and errors in modern ideology is accompanied by a dystopic view of the true church, where only a very small group of absolutely uncompromising old calendarists holds the true faith (in his book "orthodoxy and the religion of the future" he even hinted the ecumenical patriarchs are now in heresy).
On one hand his rejection of perennialism led him to be very clear in separating the Christian way from all other metaphysical and religious system, and in an age of syncretism and ecumenism this is certainly positive and needed, on the other hand he built a wall too high in his own home to the point of excluding many good Christians for minor differences of faith.
This book is a perfect example of this attitude: after a masterful explanation of the assumptions and the ideological effects of Darwinism and modern secular thought, Fr. Rose push himself into the dead end of literalist creationism.
Now while it is certainly possible that God made all things in an instant, even (deceitfully) mountains showing millions of years of gradual formation, believing this or otherwise, as long as faith in God as a creator is preserved, is absolutely irrelevant to personal salvation and should not absolutely be a reason to cause divisions and struggle among Christians.
Fr. Rose is correct in highlighting how certain assumptions of, for example, theistic evolution undermines certain core beliefs of Christianity. For example intelligent design over millions of years imply the existence of death, struggle and violence in nature before Adam, before the fall.
While this is a valid theological concern, his overall fundamentalist literalist creationism can only push away potential converts over things that are not required for their salvation, and this is unacceptable.
There is nothing worse than growing so proud of a particular interpretation to push it as if it was vital to faith, to the point of holding to it even when proven wrong or unlikely, thus exposing faith to the laughter or unbeliever over beliefs unnecessary to salvation.
A final note: the dialectical method he uses is frankly insufferable to me. Excess of literalism, an approach to the Bible and to the writings of the church fathers alike to that of protestants fundamentalists, and the constant interpolation and quoting out of context from the books of authors who supported the thesis he opposes. When he does this against secular or new age authors it is wrong but damages no one; what is incredibly serious is when Fr. Rose did this to "prove" Catholic saints he barely knows are demonic, as it borders a sin against the Spirit. (it happened in other of his books, not here)
In short, you don't have to be a Greek farmer or a monk of the fifth century to be free from modern unbeliefs. You don't need to try too hard not to be modern, to the point of becoming a caricature of your own beliefs.