Is this chemical name wrong? 2-bromobutane vs 1-bromobutane
The numbering of locants in the question is correct. In acyclic hydrocarbons, the longest chain is numbered from one end to the other.

    

The corresponding subsection of the current version of Nomenclature of Organic Chemistry – IUPAC Recommendations and Preferred Names 2013 (Blue Book) reads as follows:


  P-15.1.7.1.4 The longest chain is numbered from one end to the other by arabic numbers, the direction being chosen so as to give the lower locants to the substituent groups (side chains) [see P-14.4(f)]. (…)