This is one of the problems that arise in these discussions and I'm glad you clarified what you were thinking of.

"Industrial" spans a wide range. The problem I run into is that when I mention using Arduino or pi in industrial applications, people immediately jump to thoughts of extremely harsh environments and safety-critical applications. There are plenty of existing solutions to those problems.

Where the Pi shines is in "light industrial" tasks that a standard PC would be unsuited for (cost, size, I/O, power consumption, etc), but the environmental requirements aren't stressful. Those can be anything from counting rebar loaded onto a rack or providing help to truckers at a loading dock.

Even so, I have lots of small devices (arduino clones, Raspberry Pi) in machine control applications and they've been working very well.

Raspberry Pi is available in a "compute module" format which uses a standard SODIMM pin package... They sell quite a lot of them to commercial clients for use in manufacturing. Close to half of all Pi are used commercially, by some accounts. Stable form-factor, excellent documentation and ability to order new stock of specific models for several years after release make it very popular.

For example, I put embedded computers on drones and the first thing I do is have to figure out how to get power in that avoids the barrel jack which will almost certainly vibrate itself out. On the Pi (and most boards) that means direct power via the expansion header, but usually that means making a daughter board PCB with a suitable connector plus input protection (fuse, diode, etc). Not industrial, but any situation where you don't want to provide mains power, and you want a reliable connection means avoiding the jack.

Can you desolder the barrel connector and put on a locking molex or something?

You can, but that's irritating to do. In the case of the Pi there is no barrel connector, it's a USB port. So your only option is the header, either directly into the holes if its unpopulated, or get a 40-way female header and solder to that, or go for a daughter board.

The standard Raspberry Pi IMO isn't suited for industrial uses, but the compute module combined with a board designed with this kind of use in mind is a good start.