Thalmann and the communists were going with accelerationism and straight up wanted Hitler to win, so they blocked every coalition they could.

That’s… not how the situation unfolded.

To further understand the position taken by the KPD against the SPD, Ernst Thälmann’s 1932 speech “The SPD and NSDAP are Twins” reveals how the KPD leadership envisioned its struggle against fascism in all forms. Thälmann’s incendiary speech declared that “joint negotiations between the KPD and the SPD… there are none! There will be none!”¹³

This was not to say that the KPD did not recognize the [Fascist] threat, as Thälmann articulated that “KPD strategy directs the main blow against social democracy, without thereby weakening the struggle against […] fascism; [KPD] strategy creates the very preconditions of an effective opposition to […] fascism precisely in its direction of the main blow against social democracy.”¹⁴

It is imperative to recognize, though, that the KPD only advocated the blow against the SPD leadership. As Thälmann argued, The KPD’s policy envisioned, the creation of a “revolutionary United Front policy… [that mobilized the masses from below through] the systematic, patient and comradely persuasion of the Social Democratic, Christian and even National Socialist workers to forsake their traitorous leaders.”¹⁵

(Source herein.)