We all have our opinions on what is ok and what is not. I personally have an account for myself (and my kids have their own accounts). I would not want to be on someone else's "team" account. What is the point of logging a cache as "found" if you weren't even there to experience it. Isn't geocaching (even for numbers) still about finding caches?
Either way, it would be a good idea for Groundspeak to have specific "team" accounts, but each individual would still have their own account. Then, the teams numbers would be the total for the family or team, but each cacher could follow their own experiences through their logs.
