I have some more questions as follows:
1. Do you mean that 'very much' doesn't mean "he truly is a loner," or "The category of loner completely fits him"?
Yes, that is what I mean. "Very much" is an intensifier, indicating that something possesses a predicate in a high degree. "Out-and-out" is not an intensifier; it says merely that something is unquestionably a member of a category.
kuen posted:2. Is 'out-and-out' only used in a negative way?
Basically, yes: "out-and-out" is used with predicates that have a negative connotation. I recommend searching a corpus for "out-and-out," such as the Corpus of Contemporary American English; you'll find a host of such examples:
- "out-and-out stolen"
- "out-and-out drunk"
- "out-and-out lies"
- "an out-and-out plan of extortion"
kuen posted:3. When you describe someone is a loner, Doesn't it mean he or she is truly a loner?
Yes, Kuen. As Gertude Stein wrote, "A rose is a rose is a rose." Thus, to understand why people use "out-and-out," you need to go beyond the literal meaning to its use. It highlights a thing's membership in a negative category.