I think that part of what you object to is the habit of equating specific meaning with definitions, and equating definitions with hard-edged classifications. This is often either impossible or arbitrary and (at best) unilluminating.

If one points out a distinction, some will say that this means there must be a line between black and white. If one points out shades of grey, some will say that this means there is can be no distinction. The former use dawn and dusk to argue against day and night; the latter use day and night to argue against dawn and dusk.

This pattern, if named, could perhaps be dismissed more quickly an generate less noise that distracts from substantive discussion.
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Where meaning is real, yet inherently fuzzy, I often think in terms of prototypes: a prototypical "day" is sunny, and a prototypical "night" is dark. However, another pair of prototypes would have the Sun well above or well below the horizon. Finns may find these exotic, and instead use clock time: Helsinki, land of he midnight dusk.

Note that part of the fuzz is that the prototypes themselves can differ -- but they, too, need not be precise. Meanings remain useful provided that what is similar to one prototypes is usually similar to the other.

A prototypical "European culture" is of course harder to describe than day or night, but disaggregating what one means into dimensions (religions, political structures...) works fairly well, and can be done with respect to the specific issues addressed in a discussion.

My position supports the use of labels, but opposes the idea that they must correspond to boxes. They have meaning, but not need not have that kind of meaning. In actual discourse, however, where a label is being abused, it may be best to avoid it. (Thus, I can concede the uselessness of any label, in a prototypically abusive context.)

Words and ideas I offer here may be used freely and without attribution.