Are there fundamental reasons why (exponential) economic growth is highly desirable? One of the most widely published measures of the economy is the economic growth as a % of the GDP; i.e. the degree to which an economy grows exponentially.  In my understanding, when the rate of economic growth is declining or close to 0%, this is considered undesirable and acts are undertaken to avert recession.

In a situation where population is not growing, why do we want the economy to grow?  In other words, is there something inherently wrong with a steady state economy?

See also: Why is economic growth measured exponentially rather than linearly?
Because according to utility theory: more is better- or at least not worse (nonsatiation- or free disposal).

Your question seems to actually be: why is growth good? 

Firstly, It's axiomatic. Utility theory very formally assumes the law of nonsatiation/free disposal.  Things that result in the death of the cosmos are bad not because we are dead, but because we cannot consume and improve our happiness afterwards. Evidince: We observe that consumption improves happiness.

Second, in cases of limited resources, we have situations where optional growth paths are negative-But this is only because it allows for increased overall consumption.