Need the right balance. You don't want a keeper with a batting average of 40 who can't keep but you don't want an outstanding keeper with a batting average of 20 either making the tail long.
He hasn't averaged 40 recently.
From a #7 you really want someone who'll add the odd 100 partnership with the last batsman, and bat with with the tail all the way down.
He does the former often enough, but too often he gets out to shocking shots; which looks even worse when we've had guys like Siddle, Hilfenhaus, Hauritz, and lately Pattinson come in after him who are quite happy to put their shots away & bat through a session just to keep them out there; making him look like a prat.
For me I'd take a great gloveman who averages 20, over an average one who averages 30.
Absolutely worth 15 runs a bowling innings.
Haddin's giving away 5 too many byes an innings, dropping a catch every 2 innings or so; plus a better keeper puts more pressure on the bat when the mediums or slow bowlers are on.