One of the advantages of using a PC as a control is the availability of high quality development tools. Microsoft Visual Studio is the standard programming environment for creating software to run on the Microsoft Windows operating system. I consider Visual Studio to be a world class development environment.
While some industrial control programming software packages are impressive, it is just not practical for control vendors to compete with Microsoft on development software. Microsoft’s user base justifies the development time required to produce a product like Visual Studio. Also, Microsoft uses Visual Studio for much of their own software development, so they have internal interest in quality of it. Programming software is an aside to industrial control manufacturers. It is a necessary evil that they must provide to allow the end user to program their hardware. Most industrial control development environments are rough around the edges. Some are pretty good, but most are just usable at best. They tend to be quirky and feel thrown together. I will say that they have improved over the years, but there is no way that a typical control vendor can expend the resources needed to create programming tools that are of the same quality as a company like Microsoft, whose business is software.
In the Linux and “open source” world there are development programs such as Eclipse. Eclipse is gaining acceptance in a number of areas. Some microcontroller manufacturers are leveraging the Eclipse development by making their own plug-ins or extensions to Eclipse so that developers can use it to write code for their microcontrollers. Eclipse seems to be a strong environment, but I don’t think it compares favorably to Visual Studio, especially with respect to speed. I think that Eclipse uses the Java runtime engine. This seems to make it very slow. There may be ways to get it to run better, but every time I have tried Eclipse it has been a disappointment. I most recently used it to work on TI Microcontrollers, and it seemed barely adequate. Perhaps really strong hardware would help.