One one hand, you can surely take inhouse server, it is Acceptable for a small MSME, with non critical work. 

or companies who can take risk as under

but are you willing to take that risk ?

Reasons against in-house server …. are

1.⁠ ⁠that is very risky.. due to situation like…. local internet down / local electricity down/ RAM down / UPS Down.. then all factories in mess
2.⁠ ⁠⁠too much dependency on the sole IT manager, how can he work all 3 shifts. What will happen if there is a downtime in server at night ?
3.⁠ ⁠⁠too much dependency on 1 plant person… and all shipments may stop across all plants due to problem in 1 location
4.⁠ ⁠⁠Licences of Oracle ? to be purchased
5.⁠ ⁠⁠Licences of Windows ? to be purchased… additional cost
6.⁠ ⁠⁠Anti Virus problems risk is higher
7.⁠ ⁠⁠Ramsomware problems risk is higher

8. Somebody physically stealing away the server machine ????

9. Somebody not taking the backup at all ?

10. Handling Server Hardware problems

11.  Somebody taking backup in the server itself and not outside at all ?

as answered above, if you have appetite for all these risks… go ahead and take a fast inhouse server… Yes, some people take it. but most currently do not.