That is a very good point! I am sure there is a way, with Rules, to identify spam bot because they would not select the right value. For example you could have a custom field “Are you a robot?” and put “Yes” and “No”. There is a good chance bots will either take the first answer or not answer, and then with a rule you could clean up the mess. (that is just a workaround)
Good point! That should be a dedicated request here in the forum.