I think that right from the start, one of the purposes of iNaturalist has been to make scientifically useful observations available from all kinds of observations different people are out there making for a diversity of reasons. I think that iNaturalist is succeeding reasonably well, in the context of unsystematic data collection by people differing in purposes, interests, skills, equipment, and location. At least there are a lot of us.
One of the problems about accepting these data for use is a matter of expectations. Any data set from iNaturalist must be viewed as raw material, not a finished product. The good news is, the researcher can get a huge amount of data for free. The bad news is, he or she should skim quickly through every observation (or at least all outliers) before analysis. (Yes, I do know how long that takes – it’s the same process I go through when checking identifications of some taxon of interest to me.)
We should all do what we can to improve data accuracy, but we shouldn’t despair about the inevitable variation in this huge citizen science project.