Mesh is an alternative to regular fabric and leather chairs for various reasons including:

1.  better breath ability

2.  It provides a form that is aesthetically appealing particularly in modern corporate offices 

3.  A high quality mesh chair can wear much better than leather or fabric

The disadvantages of mesh are mainly to do with its abrasive quality and the support it offers.

Woven mesh can be abrasive and is a function of its construction.  It can wear out clothes to varying degrees depending on the quality of mesh used and the amount of use the chair is put to.   Most mesh chairs are normally always constructed with woven mesh and especially those with mesh seats.

Knitted mesh is a softer mesh that is non abrasive.  Unlike woven mesh which is akin to tennis rackets strings and only requires the frame to keep its shape, knitted mesh requires considerable support behind it.  It is therefore not commonly used in office chairs.   It is also a premium product due to the nature of its softer knitted construction.  

Common Examples of Mesh Chairs:

Woven Mesh Chair:  The Herman Miller Aeron chair is an example of a woven mesh chair.   It uses mesh in both the back and the seat.

Knitted Mesh Chair:The Cpod Chair is constructed of knitted mesh chair as it is able to get support from its patented back support system located at the rear of the mesh.   It is the only chair in the world with a back support system built into its mesh.