curtness in letter-writing does not necessarily indicate oddity.
“No,” said Stirling, with a curtness at which Weston could not take offense.
"Luggage first," said Barebone, lapsing into the curtness of the sea.
But he had carried his curtness too far, and was not prepared for the quick retort.
Her good-bye came with a curtness that might well have inspired consternation.
"Obliged to you, Hardy," he said; and only the addition of the name saved it from curtness.
That is true, replied Tessa, the sorrowfulness of the tone softening its curtness.
Rovald spoke with a curtness he did not use when the civs were present.
Though she herself was at fault, the curtness of his message aroused her irritation.
Instead, she had closed the discussion with a curtness that was not reassuring to the plotters.
mid-14c., from Latin curtus "(cut) short, shortened, incomplete," from PIE root *(s)ker- "to cut" (see short (adj.)). Sense of "rude" is first recorded 1831. The Latin word was adopted early into most Germanic languages (cf. Icelandic korta, German kurz, etc.) and drove out the native words based on Proto-Germanic *skurt-, but English retains short.