It is possible that many users actually do not go on an excursion in wild areas but usually record organisms in cities and in their very anthropized surrounding areas where wild aliens are abundant.
Many of these species would probably fall in the classes of casual or naturalized species, some others are true invasives.
Definitely, I think that could take this situation just as a datum and possibly try to analyze it. This could lead to the conclusions that iNat users are more “attracted” by alien species and that alien species are likely very abundant in the explored areas.