. is ICANN root
.com is VeriSign
example.com is Example Company LLC
www.example.com, subdivision.example.com, www2.example.com are all services, subdelegations and individual hosts within example.com
I realize this is a rapidly declining way to view the DNS but it is nevertheless the way it was designed.
sure it is helpful for organization, but when was the last time you used ssh.example.com?
RFC 1034[0] however, argues for a tree-based structure and lays emphasis on the value of branching. It being 'wrong' might have been too strong a description, how about it being 'improper'?
When I've seen SSH access being offered as a network service and not as a means to administrate other services on a network it's often been under names such as 'shell.example.com' - not exactly your 'ssh' label but an approximation.