At that time, Islamic society was quite modern and tolerant - and even often the destination for persecuted religious groups such as the Jews in Spain.
It is absolutely clear that modern Islam is, in fact, much more "conservative" than it used to be in the beginning. Indeed, the very beginning of Islam was a radically progressive movement in the region. It freed slaves, it gave rights to women, it treated with other religions and it abhorred hereditary and even defacto differences between humans. Many of the things that we now find so backwards were a) not as strict at the time and b) much more advanced than other societies in the region. A good example is the difference between the initial Islamic state and the Persian empire. The Persians didn't even fully understand that they were dealing with a sort of grassroots movement, and were constantly trying to find the equivalent of a high status ruler to talk to. But early leaders in the Islamic world were completely different, living in normal or even poor circumstances and operating in a much more democratic manner than was the norm.
Later, these societal properties were the reason that the Arabic world was able to preserve and advance science and culture. Sadly, this did not last into this century, but the reasons for this are complex and almost surely political.
I say this is important to remember because we need to realize that religion and - further - ethnicity (and of course race) are not ingrained attributes determining who is conservative. We need to remember that there was a time when Islam was the paragon of reason and rationality, while Christianity was the embodiment of fanatic action.
In the end, it is all politics, not the people. We do well to remember these things, because it keeps us from condemning other cultures, as it so often happens!