(i'm network founder of a private irc network with 300 or so users), whats the point of making a reconnect option when, for some of mirc's users, 50% of disconnects is from a kill, most of them not even being a serious /kill.
Remind me never to visit that network. Using /kill so much that a user is disconnected half the time for that reason is rather ridiculous. mIRC isn't meant to cater to that kind of abuse.
The answer to why it doesn't reconnect is simple. If a user is "killed" then in almost all cases (apparently not on your network), the ircops don't want them there. If the user keeps reconnecting when killed, they are going to find themselves banned... possibly permanently. It makes sense.
Besides, for the 0.00001% of users who absolutely want to reconnect when killed, it's a very easy thing to script.