Serious question here, if you have given it any thought and care to respond. What, exactly, from a Christian -more specifically, your- standpoint, and as it relates in this case more to Christianity than Islam, is wrong with, or bad about, Lucifer, apart from his hubris?
I did read the above Isaiah quotation, which you go on to interpret as being applicable to Islam, but, as I read, or further read, maybe even misread and that not deliberately, in the New Testament, according to St. Peter, 2nd epistle 1:19, Christians are waiting for Lucifer, translated in the KJV as the "day star," to arise in their hearts. Back to Prophet Isaiah, has Lucifer "fallen from Heaven" only to arise, at some point, in the hearts of Christians? To make the point clear, bold emphases in the following quotations are mine.
φωσφόρος, φωσφορον (φῶς and φέρω), light-bringing, giving light(Aristophanes, Euripides, Plato, Plutarch, others); as a substantive, ὁφωσφόρος (Latin Lucifer), the planet Venus, the morning-star, day-star"
Here is the verse, in full, as it appears first in the KJV, English obviously, and then in the Vulgate, in Latin:
"We have also a more sure word of prophecy; whereunto ye do well that ye take heed, as unto a light that shineth in a dark place, until the day dawn, and the day star arise in your hearts:"
"et habemus firmiorem propheticum sermonem cui bene facitis adtendentes quasi lucernae lucenti in caliginoso loco donec dies inlucescat et lucifer oriatur in cordibus vestris"