Thats a stupid reason imho. When was the last time you saw a tab flood on IRC? I've never seen one. However I see color code floods all the time. If the reason that tab is not supported is to prevent floods, then colors should not be supported either because they are the cause of most floods. Most clients other than mIRC support tabs with no problems. And, if you are worried about tabs causing a flood (which I think is ridiculous), then you'd click the [X] Strip tab characters and there you go, no floods.