I guess we will just chalk it up to just having different standards.
There is something confusing me though. What do you mean by "we"? Is it common practice where you are/in your church/in your culture for believers to point other believers to commentaries? I mean I've read some of them but would never point any believer to reading them. Where Adam Clarke specifically is concerned someone reading his stuff is not going to be able to come away from it without picking up things they really shouldn't. His whole idea of the Catholic church being the antichrist(granted that was a common theme after England split and speaks more to indoctrination than anything), the idea that Jesus had to earn his divinity and wasn't part of the trinity until he worked for it, not to mention pretty much everything he said about the rosetta stone all turned out to be absolutely wrong.
I understand.
By we, I mean everyone, even you should take caution when reading any commentary from any source. For example, Coffman pretty much repeats Clark with his views on the Catholic church the way you have described. Both commentators are considered Christian commentary.
In this case, Clark is the primary source and Coffman the secondary since he is riding on Clark's tail coat. But if Clark were to be secondary, who layed the foundation he built his house on? I think you already know this because you mentioned it above. Hence, we are influenced by our society.
Now then, I do not ascribe to those views, (RCC is the anti Christ) and those views are not tolerated on this site. But that does not mean that everything Clark wrote was wrong, so where Clark got it right, we can embrace those truths, and we should with any commentary from any author.
Here is the problem the way I see it.
If I give you commentary on Genesis, and you agree then you will more than likely share those thoughts. However, if I start my commentary by telling you Pope John Paul wrote the Theology of the Body, and this is what he said about Genesis... you may reject those truths simply because they are related to the Pope.
We see right away then that the same message can be rejected or accepted not by its content, but rather by who is speaking it.
Why is this?