… because it was during the 1850’s that they were developed. The textile industry at the time was booming, and the increased demand for cost effective, easy to produce and replicate and apply dyes were in great demand.
The economic limitations in growing, gather, harvesting, and processing natural dyes on such a large scale, combined with large scale farms and specialized agricultural methods made synthetics that could be produced in a factory a symbol of the era.
Synthetics were powerful, “stuck”, cheap, and intense in color compared to naturals.