Spiral,
I'm not a security researcher, but I think ssh is generally considered a pretty secure way to access a remote machine. I presume therefore that you consider it dangerous primarily because it gives the customer the ability to do things that they wouldn't otherwise be able to do. That extra power can be very effectively locked down though, and memory/CPU monitoring and automatic process killing etc. can be used (and be useful for general hosting anyway). So sure, precautions and preventative measures do need to be taken, and hosts (or the provider of the software they use...hint, hint) need to know what they're doing, but I think characterizing ssh access as necessarily "extremely" dangerous and not something for a "smart" shared hosting provider is overcooking it slightly. ;-)
I also have to take issue with the idea that it would necessarily be wrong for me to look for shared hosting if I have particular applications or unusual usage where I require SSH access and multiple users. Surely the main measure should be whether my account's usage remains light and doesn't disrupt the other users on the machine?
One of my reasons to want ssh access is because I want to run rsync - it's more reliable than FTP, it's quicker, and it uses less resources. Another is that I want to host small Mercurial and Git repositories with light usage on subdomains with "push" (commit) access for the users. I also want to host a domain where I and another person can collaborate on a redesign of a charity website (using rsync), but I don't want that other person to have access to my personal sites. I could go on with other examples of reasons I'm finding ssh access and the ability to create my own unix users and groups useful on my Dreamhost shared hosting account, but probably you get the idea. ;-)