The last time congress changed the de minimus threshold, it gave the following context in the corresponding Act:
FINDINGS.—Congress makes the following findings:
(1) Modernizing international customs is critical for United
States businesses of all sizes, consumers in the United States,
and the economic growth of the United States.
(2) Higher thresholds for the value of articles that may
be entered informally and free of duty provide significant eco-
nomic benefits to businesses and consumers in the United
States and the economy of the United States through costs
savings and reductions in trade transaction costs.
(b) SENSE OF CONGRESS.—It is the sense of Congress that
the United States Trade Representative should encourage other
countries, through bilateral, regional, and multilateral fora, to
establish commercially meaningful de minimis values for express
and postal shipments that are exempt from customs duties and
taxes and from certain entry documentation requirements, as appro-
priate
What exactly does suggest to you that this is intended for personal, non-commerce use?