I'm not sure your logic is quite correct. While I admit I am surprised CLE is still open 10 years after the merger, there are some signs of life. The last 2 bids have had Captain vacancies, therefore the death through attrition is not the case.
The point to point leisure flying is probably good for CLE, but this flying will probably dry up as the flying picks up and we return to more hub and spoke model.
CLE is also a good backup for both ORD and EWR and sometimes IAH. We don't get huge delays the big hubs get and are able to get flights out when needed.
CLE has a great maintenance base and does a lot of work on the overnight aircraft.
Will CLE outlive ORD or SFO as a base, no. Will it enable the current pilots to drive to work and provide for the families that want to continue to live in Ohio for at least a few more years, I hope so.
If you want it, bid it.