With the 24th ranked payroll, Arnold has the Brewers 100 games into the season with MLB's best record, and honestly has many options for players not on the current 26-man active roster either rehabbing or sitting in AAA that could help add to the club down the stretch (Gasser, Cortes, Henderson, Patrick, Peguero, Yoho, Frelick, Mitchell, Quero, Hoskins, etc/etc). I think SS/3B is probably the spot if the Brewers want to make a splash at the deadline where they should go - but both Durbin and Ortiz have been a big part of the recent surge the Brewers are on, too. They've also got a deep enough farm system where overpaying a bit for a key bat actually makes sense at the deadline to help sort out future 40 man roster decisions the next few offseasons.
To answer the title of this thread, perhaps Arnold should start getting criticism from Brewer fans when he gets poached by a different large market team after winning consecutive MLB executive of the year awards.