The job I currently do combines both, although more electrical we do write and use code to fault find.
I'll give an example, the other day a large incineration plant would not start. The plant is controlled by both electrical panels containing relays and a programmable controller (PLC). We can 'watch' the code live while the plant begins starting to help pin point where the fault is, and where it is coming from. We did this and narrowed it down to a fault on one of the PLC input cards. We then watched the bank of relays connected to the input card and the plant failed every time a particular relay pulled in. Tested the relay, which was reading low resistance, replaced it and all was good.
The code we use isn't computer science level, most electricians comfortable with using a computer could pick it up after a couple of training courses and a few months in the field, but it is getting more complex.
However some PLC code is written in structured text these days, which is closer to the sort of code you may study on a CS degree. In the future it could be likely the company gives the electrical and electronic work to traditional electricians, and the more complex PLC work to a dedicated department, most likely with a CS background, but the cost savings to a company if someone could do both is huge as most times, both skills would be required at the same time.
Although saying that, most companies will try and keep all their PLC code written in ladder (this type of code looks more like an electrical drawing of relays) to avoid having to take on more qualified and therefore more expensive employees to complete the same tasks.