Slightly mangled interpretation.
Yes, CO2 emissions *are* a problem.
However, they are not the only undesirable emission an internal combustion engine produces whether operating as designed or otherwise. The problem you’re alluding to is that most/all governments and their associated bodies spent twenty odd years selling the public that CO2 was the only pollutant. Hence a generation of car buyers who feel cheated when they discover their vehicles may have been making low statistics for CO2 but were actually busily poisoning everyone around them and destroying the planet in many other ways.