Do they not realise that this will inflate their citation counts (given shared names) to ridiculous levels (and leave them looking unprofessional)?
Or is it a deliberate strategy to raise profile?
For example, I just looked at UNSW's top cited authors on GS to get a sense of their relative strengths, and two of the top three are such cases:
https://scholar.google.co.uk/citations?view_op=view_org&hl=en&org=4274056836244091944