Even some of those chinese clone PLCs are not spectacularly reliable... This is a professionally made device, developed in partnership with Finder which is a company with 70year of experience in making relays and other mission critical industrial equipment..
I'm quite willing to entertain that you are trying to get into the market and that these issues may be resolved with this product but you have a large reputation mountain to climb first.
You have to build reputation not try and add it afterwards.
To note I use Arduino projects usually for one off simple bench automation but nothing further than that. I tend to use them as a host for flat avr-libc / avr-gcc projects though, mostly because the old IDE and toolchain was absolutely dire.
That's the basic mechanism of why so much advertisement is just about brand awareness, not talking about quality at all: "I've heard a lot about them, and not everything has been bad" is less bad than "never heard about them, even if they were really terrible I wouldn't know"
Marketing gets you to the testing table. But better not have any skeletons in the cupboard.
Edit: I suspect you're confusing engineering for the niche sector of makers, the latter of which are driven by fads and marketing (sorry if I piss anyone off there).
It's possible that Arduino fantasizes about taking over large fractions of the industrial PLC market and if that's the case I'll chuckle agreeingly with everybody ridiculing them, but I believe that there could far more reasonable and realistic opportunities for them to stretch a little in that direction.
Arduino products rarely sell to people who do any form of QC or comparison shopping - they sell to people who buy the first thing on their mind.
Most of the Chinese embedded companies are engineering groups that understand they are filling the low end of the professional cost-quality curve, but they are still on that curve. For what you pay, they make a great product.
It also seems to me that your definition of the word "reliability" isn't agreeing well with others - to me it seems that these industry guys are using the word along "semi believable certification documents and soft established likelihood of not catching fire" whereas yours are more along "blind idolization for moral qualities seen in individual corporate employees". That might need a fix.
It's fine from a easy, hacked together hobby project point of view, but that's an entirely different thing.
It's like Python vs Rust. I wouldn't introduce a beginner to programming with Rust, but I also wouldn't program my manufacturing line (or whatever) with Python.