I wonder if having both a Thank you / Like button and a slightly less obvious Confirm ID button could take care of a large part of the blind/thank you agreeing. Of course, notifications for Thank you’s could also be turned off.
In addition, another possibility could be to make the Confirm ID button more dynamic and scary by being explicit with the community taxon. For example, someone observes an unknown plant and IDs it as Plantae and then an identifier comes along and identify it as Carex retrorsa. The Confirm ID button could then change to “Confirm this is Carex retrorsa”. I’m not sure of the consequences of this on the website though.