Why aren't chaperones considered catalysts?
I don’t think you are wrong. Actually molecular chaperones have been named enzymes in some texts. The molecular chaperones comprise several unrelated classes of proteins that have rather different functions.


  Most molecular chaperones are ATPases (enzymes that catalyze ATP
  hydrolysis), which bind to unfolded polypeptides and apply the free
  energy of ATP hydrolysis to effect their release in a favourable
  manner.


It is also made evident in the way some of them function (they possess some ATPase activity), it suggests they’re kind of  catalysts  enzymes:


  They function in an ATP-driven process to reverse the denaturation and
  aggregation of proteins (processes that are accelerated at elevated
  temperatures), to facilitate the proper folding of newly synthesized
  polypeptides as they emerge from the ribosome, to unfold proteins in
  preparation for their transport through membranes.


Two classes of molecular chaperones have been well studied. Both are found in organisms ranging from bacteria to humans. 


The heat shock proteins 70 (Hsp70)


The first class is a family of proteins called Hsp70. They function in an ATP-driven process to reverse the denaturation and aggregation of proteins (processes that are accelerated at elevated temperatures), to facilitate the proper folding of newly synthesized polypeptides as they emerge from the ribosome, to unfold proteins in preparation for their transport through membranes and to subsequently help them refold.


Chaperonins


Are also heat shock proteins that form large, multisubunit, cagelike assemblies that are universal components of prokaryotes and eukaryotes. They bind improperly folded globular proteins via their exposed hydrophobic surfaces and then, in an ATP-driven process, induce the protein to fold while enveloping it in an internal cavity, thereby protecting the folding protein from nonspecific aggregation with other unfolded proteins.

Other chaperones e.g. Hsp90 proteins (have a regulatory role in that they induce conformational changes in nativelike substrate proteins that result in their activation or stabilization) and Trigger factor (prevents the intra- and intermolecular aggregation of newly synthesized polypeptides as they emerge from the ribosome by shielding their hydrophobic segments) However, unlike most other chaperones, trigger factor does not bind ATP.

Enzymes are more or less catalysts in biological systems, so yes its right to synonimise them with catalysts.

References


Biochemistry (Voet and Voet) Section 9.2 Folding Accessory Proteins, Molecular Chaperones: The GroEL/ES System.
Lehninger Principle of Biochemistry Chapter 4, Protein Denaturation and Folding.
Biochemistry R. Garret, C. Grisham. Chapter 31 Completing the Protein Life Cycle: Folding, Processing, and Degradation