My personal opinion is i still like net-force and think it should not be disabled.
You are right that the challenges are buggy, this is know since ages.
The bug is really weird and requires you to enter your solution up to 10 times to make sure it`s right or wrong, still the challenges are solveable.
I think many challenges there are quite unique, and good. For example there are some very nice programming challenges ("Do you like the Euro" is one of my favorites).
Also the challenge with that bitstream validation algo is very interesting, whereas i forgot the title of that challenge.
Net-Force might look dead, unadministrated, and can be abused by bots easily, but it does not annoy me enough to disable it here.
My hope is there will be some new admin someday
Of course, more comments are welcome.
This is my personal opinion of the status of net-force and i will try, like always, respect the opinion of others and decide not only based on my personal opinion.