I think the "it was native and abundant so nobody used it because it didn't demonstrate wealth" explanation is far more plausible given that the same can be observed with many native plants and spices in other parts of Europe.
TFA mentions that spices were categorized as "sweet or strong" and given that coriander was seen as "strong" it competed with fancier imports. This preference likely "trickled down" making the spice seem less appealing to the masses, especially with increased social mobility in more recent history.
TFA mentions that spices were categorized as "sweet or strong" and given that coriander was seen as "strong" it competed with fancier imports. This preference likely "trickled down" making the spice seem less appealing to the masses, especially with increased social mobility in more recent history.