-Dow epic-ly fails at co-aligning employee performance with employee rewards (pay raises). The people that rise to the top are always those that play the game the best. Technical performance is 'rewarded', but often the spotlight is stolen by someone else. These sorts of thing are common in corporate america; Dow is on the worse end of it.
-Core R&D is not the best place to be right now (recently chopped pretty heavily), and based on trends in the chemical industry, it doesn't look good for the future. The degree to which Dow's businesses value Core R&D varies, but there historically have been complaints.
-Midland sucks. It's a good place to live if you want to raise a family, but other than that there isn't much going on in any regards.
-although Dow has a good culture in terms of accepting different races/genders/etc..., it has a very narrow personality type. Everyone at Dow is Type A, and Dow employees struggle heavily with doing anything differently than they used to. Dow really struggles with non-conventional solutions and thinking outside of the box.
-High-level management change every year or two really undermines overall group performance.
-mid-level management (e.g. most people's managers) are usually some combination of ineffectual, impotent, or uncaring. On average I've had a new manager every ~10 months, and not a single one really helped my career much. Some were well intentioned, but constrained by 'rules'. Some didn't care. etc...
-When you factor all of these things together, could think that Dow would struggle with talent retention (e.g. keeping high performers versus people who play the game well). This is a well known problem at Dow. It is very common for people to getting industrial training at Dow and then go off to another company where they are more highly valued.