It's a pretty naked sympathy appeal for money. "Honestly, if everybody contributed just 3 extra cents on their 1040 tax forms", etc.
Anyone around here familiar with the "Iron Law of Bureaucracy" coined by Jerry Pournelle? For every sufficiently large organization, self-preservation and expansion inevitably crowd out the organization's ostensible purpose. SETI's primary purpose is not to find extraterrestrial intelligence. SETI's primary purpose is to ensure the continued existence of and wages paid to SETI. Actually finding the aliens is a secondary goal.
(I am not ragging on SETI in particular here, that happens for every bureaucracy. The primary purpose of NASA is to get NASA and its contractors hired and paid, not to explore space. The primary purpose of TSA is to get TSA workers hired and paid, not to secure airways. The primary purpose of unions in education is to get themselves hired and paid, not to educate. These organizations do accomplish their stated goals to some and varying degrees of success, but never at any cost of imperiling their own demesne.)