Conversation so far:
What is one-to-one correspondence?
Georg Cantor proved for any positive integer n, there exists a 1-to-1 correspondence between the points on the unit line segment and the points in an n-dimensional space.
What year was Georg Cantor doing his work on 1-1 correspondence?
In 1874, Georg Cantor's Crelle paper revealed his beginning work on his notion of a 1-to-1 correspondence.
What is Crelle's Journal?
Crelle's Journal, or just Crelle, is the common name for a mathematics journal, the Journal für die reine und angewandte Mathematik.
How was Georg Cantor's paper accepted?
The objections to Georg Cantor's work were occasionally fierce: Leopold Kronecker's public opposition and personal attacks included describing Cantor as a scientific charlatan, a renegade and a corrupter of youth.

Question: Why did it displease Kronecker?
Self-contained rewrite: Why did Georg Cantor's paper displease Kronecker?