Wolf put it well.
Another point to consider — institutions often want their donors to publicize the donations as it often motivates others to give as well, for a variety of reasons. Sometimes other donors will consider the fact that someone they know has given big donations to this institution as a sort of “haskama”, and it makes them more willing to give. Sometimes it’s plain old fashioned peer pressure, and sometimes it helps build excitement. Also if the honor being received is in the form of a fundraising event (like a dinner honoree, or even a Chanukas Habayis for the building they named), the hoopla surrounding the event also leads to more donations from friends and associates of the honoree. The point is that there are times when a tzedakah will literally beg a donor to accept an honor, even if the donor would prefer to give quietly. (Obviously there are those who run after Kovod, but just because someone is getting recognized doesn’t mean he was looking for it.)