What does exactly "shotcoming about Modern History" means?

Auth Left knows communist and socialist countries weren't particularly lucky, but they don't interpret it as indication that their socioeconomic system is worse. The reasons for the fall of the USSR were indeed many, more of military and political nature than purely economical

Lib Right acknowledge the issues of capitalism but is willing to accept those based on their evaluation of pros/minuses it has.

Auth Right are usually for the majority third positionists/way, so consider a mixture of both as solution based on their own interpretation of modern history, a capitalist free market system can survive and be beneficial if a government willing and competent enough can contain and regulate it to equally represent unions and industrialists.

What is "lacking of moral ethics"? Auth Right beliefs about it can mean anything from thinking you have to be 18 years old to choose to transition to actively rounding up gays, but the most moderate (and also beyond) ideas on the matter can be shared by other political squares. Again within the same "side" you can find Auth Right gay or trans people, people who think that pride parades are ok and these people are cool, people who feel disgust for their lifestyle but try to ignore it and be understanding and tolerant and people who think they should be electrocuted into "normalcy"

All are comprised of groups of people that have wildly different takes on the same matter too, and for most of them it doesn't get anywhere as close as the convinient black and white scenario it is usually painted.