Amortisation is the equivalent of depreciation for intangible assets.
The balance sheet value of intangible assets is even less related to their economic value than that of tangible assets. Intangible assets created within a company (as opposed to bought in) are not even shown in the accounts at all. The case for excluding amortisation from profit numbers is even stronger than that for excluding depreciation.
The rationale and methodology for dealing with the value of tangible assets through depreciation or depletion is clearer than that for amortising intangibles.