Halliday & Matthiessen (2014: 730):
This kind of nominalising metaphor probably evolved first in scientific and technical registers (cf. Halliday, 1967b, 1988), where it played a dual role: it made it possible on the one hand to construct hierarchies of technical terms, and on the other hand to develop an argument step by step, using complex passages ‘packaged’ in nominal form as Themes. It has gradually worked its way through into most other varieties of adult discourse, in much of which, however, it loses its original raison d’être and tends to become merely a mark of prestige and power. Notice that when clausal patterns are replaced by nominal ones, some of the information is lost: for example, the Classifier + Thing construction alcohol impairment gives no indication of the semantic relation between the two and could be agnate to alcohol impairs (alcohol as Actor), alcohol is impaired (alcohol as Goal), and maybe other transitivity configurations besides. The writer presumably knows exactly what it means; but the reader may not, and so this kind of highly metaphorical discourse tends to mark off the expert from those who are uninitiated.