Masking the symptoms is NEVER better than solving the problem. You can keep kicking out the floodbots till hell freezes over, unless you do something to prevent them from joining back, and prevent others from joining as well, the flood is gonna keep going. Setting a temporary +i is the only way to stop them from rejoining (bans don't cut it, especially on networks where you can connect through proxies).
PS: "only way" is relative, on DALnet you can use +R to prevent floodbots from joining too.
PPS: don't take that "till hell freezes over" too literally -- it already did a few years ago.
