Why do conservatives claim that Hitler was a leftist?

[JHB]

56. The early NSDAP did have a number of "leftist" position points...

...that appealed to socialist-favoring workers. For instance, from their original "25-Point Program" of 1920:

10. The first obligation of every citizen must be to work both spiritually and physically. The activity of individuals is not to counteract the interests of the universality, but must have its result within the framework of the whole for the benefit of all. Consequently we demand:
11. Abolition of unearned (work and labour) incomes. Breaking of debt (interest)-slavery.
12. In consideration of the monstrous sacrifice in property and blood that each war demands of the people, personal enrichment through a war must be designated as a crime against the people. Therefore we demand the total confiscation of all war profits.
13. We demand the nationalisation of all (previous) associated industries (trusts).
14. We demand a division of profits of all heavy industries.
15. We demand an expansion on a large scale of old age welfare.
16. We demand the creation of a healthy middle class and its conservation, immediate communalization of the great warehouses and their being leased at low cost to small firms, the utmost consideration of all small firms in contracts with the State, county or municipality.
17. We demand a land reform suitable to our needs, provision of a law for the free expropriation of land for the purposes of public utility, abolition of taxes on land and prevention of all speculation in land.
18. We demand struggle without consideration against those whose activity is injurious to the general interest. Common national criminals, usurers, profiteers and so forth are to be punished with death, without consideration of confession or race.
19. We demand substitution of a German common law in place of the Roman Law serving a materialistic world-order.
20. The state is to be responsible for a fundamental reconstruction of our whole national education program, to enable every capable and industrious German to obtain higher education and subsequently introduction into leading positions. The plans of instruction of all educational institutions are to conform with the experiences of practical life. The comprehension of the concept of the State must be striven for by the school (Staatsbuergerkunde) as early as the beginning of understanding. We demand the education at the expense of the State of outstanding intellectually gifted children of poor parents without consideration of position or profession.
21. The State is to care for the elevating national health by protecting the mother and child, by outlawing child-labor, by the encouragement of physical fitness, by means of the legal establishment of a gymnastic and sport obligation, by the utmost support of all organizations concerned with the physical instruction of the young.

The other points are those we more commonly associate with right-wing nationalists these days.

This continued through the Strasser wing of the party, favoring the brothers Gregor and Otto Strasser.

The name Strasserism came to be applied to this form of Nazism that developed around the brothers. Although they had been involved in the creation of the National Socialist Program of 1920, both called on the party to commit to 'breaking the shackles of finance capital'.[1] This opposition to "Jewish finance capitalism," which they contrasted to "productive capitalism," was shared by Adolf Hitler himself, who borrowed it from Gottfried Feder.[2]

This populist and antisemitic form of anti-Capitalism was further developed in 1925 when Otto Strasser published the Nationalsozialistische Briefe, which discussed notions of class conflict, wealth redistribution and a possible alliance with the Soviet Union. His 1930 follow-up Ministersessel oder Revolution ('Cabinet Seat or Revolution') went further by attacking Hitler's betrayal of the socialist aspect of Nazism, as well as criticizing the notion of Führerprinzip.[3] Whilst Gregor Strasser echoed many of the calls of his brother, his influence on the ideology is less, due to his remaining in the Nazi Party longer and to his early death. Otto, meanwhile, continued to expand his argument, calling for the break-up of large estates and the development of something akin to a guild system and the related establishment of a Reich cooperative chamber to take a leading role in economic planning.[4] Strasserism, therefore, became a distinct strand of Nazism that, whilst holding on to previous Nazi ideals such as ultranationalism and anti-Semitism, added a strong critique of capitalism and framed this in the demand for a more "socialist-based" approach to economics.

It is disputed, however, whether Strasserism effectively represented a distinct form of Nazism. According to historian Ian Kershaw, "the leaders of the SA (which included Gregor Strasser) did not have another vision of the future of Germany or another politic to propose." But they advocated the radicalization of the Nazi regime, and the toppling of the German elites, calling Hitler's rise to power a "half-revolution," which needed to be completed.

To keep a long story short, their faction was eliminated during the Night of the Long Knives purge.

So, during the 1920's there's an argument to be made that they were socialists, as long as you remember that it was a faction of the party, with an opposing faction. And it was the Strasser faction that was put to the knife, by Hitler loyalists.

But Hitler, particularly once he consolidated power and didn't have to "play nice" to anyone? Calling him "leftist" or "socialist" is so ignorant it's more of a vacuum than a gap in knowledge. It actively sucks in garbage.