By qualifiers, I mean words like; "some", "many", "it appears that", "maybe", "I think", "it seems", etc.
Not doing so when referring to a group or class of people, will immediately label you as a bigot in the eyes/ears of your readers/listeners and not doing so when stating facts, can label you as a careless or dogmatic thinker.
You should never or very rarely refer to a whole race of people, a religious sect, a political party, or any large group as "them" or "they" because what you are saying very rarely refers to every member of the group.
We think of too many groups as all having the beliefs, qualities, or characteristics of a few of their more radical members. A pertinent example is Muslims. Most Muslims don't interpret the Koran as telling them to kill all non-believers. Most Muslims loosely interpret what their Koran says and don't advocate Jihad. For that matter the King James version of the Bible could just as easily be interpreted as saying to kill all non-believers but it is usually given a looser interpretation.