There are many reasons why secular scholarship is not appreciated by many of the users on this website, myself included. I will outline a few of the reasons.
The basic problem is assuming that by being detached, the scholars somehow gain a superior vantage point from which to study the issues. The problem is that they are trying to understand something from the outside that was deliberately written by and for people on the inside, with the assumption that the readers all buy into the same basic premises. So they often miss basic cultural aspects of what they study. For example, they often try to ascribe motivations for why this Rabbi held this view based on whichever circumstance, even though to someone who lives within the framework of the Jewish law, the supposed motivation does not make sense.
Because of this issue, many scholars just assume that there is no point to
In addition, many of the secular scholars' knowledge is only impressive to people without a thorough background in Torah study. I can't tell you how many examples I have seen of supposed academic scholarship that would be laughed out of a yeshiva. A friend of mine once had a class in law school in which a visiting professor put up a page of Talmud and then misidentified the main commentaries on the page. When my friend pointed out her error, she replied that she was an academic and knew what she was talking about, never mind that my friend had studied Talmud since before his bar mitzvah.
In another case, I went to see an exhibit of archaeological artifacts from Israel at a museum. There was a vessel from the second Temple era with the word korban on it. The label speculated that it may have been used to carry offerings to the Temple. Apparently, the "scholars" did not know that these vessels are described in the Mishnah (which is from shortly after that period), in the tractate called Vessels, as being used to store the meat of offerings.
An even deeper issue is that the major books such as the Mishnah, Talmud, etc. were never meant to be understood without a teacher. When it comes to the Rambam's Mishnah Torah, the Rosh (R' Asher ben Yechiel) said it could not be understood without knowing the underlying Talmudic passages. There are rules, never specified in the Mishnah or Talmud, for how to extract the final ruling from their discussions. These were passed down orally, and only collected into writing in later generations.
So basically, academic and secular perspectives are often not appreciated because they are not valid methods of analysis. They rely on deliberately discounting important context just because otherwise they would have nothing to say.