To my knowledge, Gary Morse is not running for public office. That is the only reason I know of why a person should disclose all their holdings/income/contributions/taxes.
But then, very few of the millionaires in Congress voluntarily disclose
their wealth and donations:
"
...Just 17 out of the 535 members of Congress released their most recent tax forms or provided some similar documentation of their tax liabilities in response to requests from McClatchy over the last three months. Another 19 replied that they wouldn’t release the information, and the remainder never responded to the query..."
Read more here:
Most members of Congress keep their tax returns secret | McClatchy