It all boils down to an individuals choice. Each brewer needs to decide what they want and how much they want to spend for it. There are absolutely many options available. Here's an example of my point... I brewed once with a guy that had a blingy computer controlled system. All was going well. I decided to check the pH and gravity of the mash near the end of the cycle I guess because I was bored (I brought my box of tools, he had no pH meter or refractometer, and only checks SG before pitching). I knew something had gone south so I asked him about it. The pH was like 6.2 and the gravity was nowhere near indicating conversion was complete. His response was "I have no clue, I just copied the file over and hit start, it worked last time". Big automation, but the toys didn't replace basic knowledge. He went on to say something like "for what I paid for all this, it better work".
For work, we have this nasty habit of making tasks and jobs easier, more cost efficient, more repeatable, more accurate and safer, and putting people out of work by replacing their jobs with equipment... All through automation. ROI happens over time and there is always a price to pay.
When I decided to go electric and build a new rig, many images ran through my head. I/O boards, solenoid valves, flow meters, level sensors, touch screens, maybe an SBC and more WPF components than carter has liver pills, Maybe a little 8051 derivative, microcrap or an ARM and a few days with the Kiel compiler, opto's... Oh boy, what could have been. Archive after archive or prior PID and servo code projects laying around. I even pulled out a few Siemens and Allen Bradley PLC's I had laying around and started counting I/O's
Then reality hit. Do I really want to spend the time on this? Brewing is my escape from work. Do I want to create something that 15 other people have already and try to sell it? Naaaah, don't need the headaches. I'll keep the career and hobbies separated. That $48 PID that holds a degree or so will do me just fine and it's already got the RTD input block, filters and ADC designed in, and hopefully its at least slightly proven out
If you want aerospace level repeatability, you need to go much further than I/O's. Humidity and barometric pressure sensors (need that boil off and volume exactly while matched to the timing, right?). High temp flow meters so conversion and sparge happens identically. RTD's at multiple levels in the grain bed. Optical recognition of the grain grind. Augers to move, weigh and dump hops (a spectrometer might be helpful to know the AA for every leaf or pellet). Dissolved oxygen sensors and continuous pH monitoring. Might want to consider turbidity and TDS sensors also. Ok, i'm joking, InBev doesn't even go that far. The point is no matter what you automate, there can always be more and the human has to make some choices and take actions. At some point, our taste buds are the limiting factor of "is this the same beer as before?"
If someone has the bucks and wants to buy the wiz-bang automation, great. There is nothing wrong with that. Or if someone has the skills, time and motivation, awesome go for it.
A brew rig is a tool. You still have to know how to use it and have some knowledge and a little experience under your belt to master it. As a pilot, we all want automated cockpits, fancy navigation equipment, and digital displays, but those toys do absolutely nothing to make you a better aviator.