I see no urgency to delete members. It's not like it's a bookshelf with limited space, that needs tidying up. Members do return after 6 months, and what harm are they doing while there are at the bottom of the members list (ordered by last visit)?
Inactive Members

I once had an account, it's still alive, but I haven't logged in since, oh, maybe 2 years. It was tracked by a certain person (parents do the strangest things), and I wanted to remain hidden.
Point is, most people who return to chesscom after a hiatus will either have said prior to leaving that they would return, or make a new account and start fresh. So I think unless stated that someone would return, delete after 2*pi months.

"It was tracked by a certain person (parents do the strangest things), and I wanted to remain hidden."-This sounds disturbingly familiar!
Elroch, they do no harm by staying in the group, but I think an accurate assessment of our group's abilities is significant. Sure, I could keep a list of inactive members and not delete, and just subtract them from the rest of a team whenever I plan for a new activity, but this is more complicated.

The reason behind deleting inactive members is this:
If you have 100 members on your list, who is going to accept or send challenges from/to you? Other groups with about 100 members. So, if you only actually have 50 active members and your opponent has 100 active members, who do you think will do better in the match?
Unless you challenge much smaller groups than your own, which undermines your credibility to a degree, your opponents will come with more, higher-rated players.
Thank you everyone for your input on this matter. I am in favor of it myself, but I wanted to make sure to wait to hear if there could be any objections that would make me change my mind. Phobetor, the purpose in my view would be to get a more accurates assessment of our groups real abilities, and possible new activities based on the number of active members. I will wait a little longer to listen more before I start to delete those who haven't logged in for 6 months.