Why do you use catalysts if they increase the rate of forwards and backwards reactions equally?
In a simplified representation, a catalyst lowers the overall activation energy while going from initial state A to the of the products B along the reaction coordinate. The interference of the catalyst on the reaction alters the reaction mechanism, renders alternative pathways accessible, which then may be  more favourable than for the reaction in absence of the catalyst. Catalysts are deployed regardless if the overall reaction is exothermic, or endothermic. And, because of the relationship described in the Eyring equation, changes in the free activation enthalpy influence rate constants.



For the instance of a heterogeneous catalysis, the picture is simplified as assuming energy chances for adsorption of the starting material(s) to and subsequent desorption of the product(s) from the catalyst were non-significant in the overall picture.

You are right that it may ease both the forward, as well as the backward reaction.  However, in absence of catalyst, overcoming the activation energy at all were just too expensive, even if the reaction $\ce{A -&gt; B}$ drawn here happens to be an exothermic one.  

As examples, think about the hydrogenation of benzene; in absence of Nickel there were practically no reaction at all, even at elevated temperatures.  Numerous biochemical reactions were unable to proceed in absence of a catalyst at ambient temperature, too.