I don't think it's misleading, but like most statistics, I wouldn't want to rely on it completely. To me, WHIP, ERA, and K:BB are a pretty good trinity of stats... IP is also very important to me for starters, and W-L to a much lesser extent. It can be misleading if you have a porous defense, I guess, or if a lot of the hits that are falling in are fluky... but the walks are inexcusable.