In many cases, those things which make Christianity morally and spiritually distinct from the surrounding culture are fading from much of Protestantism. I'm not saying that Protestants alone are guilty of this; others are, too. Souls feel drawn to, say, Islam, because most of the Muslim world has some concept of fairly iron-clad moral absolutes, guidelines, no-arguments-allowed beliefs, and a passionate (albeit often misguided) devotion to its prophet, book, and deity. That appeals to people. The women are generally veiled, the men are strong leaders in the home and the mosque, there is a great deal of respect for the contents and commandments of the Quran, and Muslims, for the most part, are very sure about what they believe and what is pleasing to Allah, even if the surrounding world feels that some of those standards are archaic, misogynistic, bigoted, fanatical, or baffling.
A growing number of Christians, however, reject much of what the New Testament commands and prohibits with excuses such as "times have changed", "that's just Paul", "our understanding of God has changed", "Jesus didn't say that directly", and "we must change to remain relevant". Whereas a Muslim might in contrast say or feel something like "I don't care which century it is, homosexuality is punishable by death, I have every right to take a second, third, or fourth wife, my eleven year old daughter is going to marry her first cousin who's twenty-two because I say so, and if any of my children even adopt the ways of the kufurim, they are both literally and figuratively dead to me". However awful much of that might sound to us, it reveals a deep and essential devotion to Islam far greater than any concern for public outrage or even sentiment. If Christians had similar zeal for Christ Crucified, the Scriptures, the Apostles, and holiness, we wouldn't have this problem.