5e doesn't try to remove those prejudices or mistrusts - they ARE there and present, and teiflings are often mistrusted, ostracised or maligned, that's still there - it's just been made clearer that it's mostly unjustified, and that they are (in reality) no more naturally or intrinsically disposed towards evil alignments than any other mortal creature.... though as with anyone who is often treated that way, they often find themselves pushed into those sectors of society as a result, so you do find a lot of cruel, selfish and mistrustful teiflings, but it is, specifically noted, not because of their blood, and not inherent to their being.
