How can you explain that this "clunky and unreliable" OS is the standard in business?
Are all IT departments stupid?
Speaking as the manager of IT in a corporate environment, I can tell you that we have always run a mix of Windows an Mac systems - depending on the need of specific users/functions. We buy Windows PC because they are cheap(er) than Macs - typically we use desktop PCs rather than laptops, but on a 5 year capital investment program, Dells cost about half what a comparable Mac would be.
The thing is though that this is
only the capital investment program. This is the way the business costs it's IT, because hardware is the up-front 'charge' to our balance sheet to be amortized over the 5 year plan. This isn't because
we think in those terms, but because the bank does.
When we look at the actual functional total cost of our IT, the picture is very different. Support costs for our Macs is a fraction of that of Windows PCs, downtime for Macs is virtually non-existent in comparison to Windows systems, and software costs are much lower.
But in productivity terms, there's almost no apparent or measurable difference.
To us, the great downside in IT is Microsoft. Not Windows as such, because even 8.1 was perfectly adequate and operable, but the fact that MS have a habit of pushing patches urgently, which are sometimes very destructive to stability, and not unusually have to be re-issued. The result is that we need to use patch management to control and block what patches we do allow, when we allow them, and what we need to block. This is somewhat expensive in terms of the software, service, and the technical support, particularly if MS release and push a zero-day patch, or we get an 'all hands' condition where something like a buggy patch gets through and destabilizes everything. This isn't frequent (it was for a while) but it happens.
Our Macs are more popular with users - not just their designated users - but when we investigated the option to switch the entire fleet to Macs, the partners were advised by the business manager that the bank were baulking at a capital spend of almost twice the investment of the past, even though the total 5-year whole-life costing leveled the disparity, and actually tipped it marginally in favor of buying Macs. The bank, as they rightly pointed out themselves, were only funding the hardware, not the ongoing costs, which the business would be funding from operating revenues.
Personally, as I've said elsewhere, I'm a Windows and a Mac user, and find the practical differences in operability relatively minor. If I were looking purely at cost, I'd buy Windows PCs all day long, and in the business environment where the bank think in short-term investment/recovery terms I easily see the constraints - even the benefits of buying PCs given the heavier support load they typically need (thus IT jobs). I do however still prefer macOS and Macs, simply because they are far more readily suited to consistently 'boot and use'.
Anyway, that was specifically to address your question, because no, we're not stupid, just constrained by budgets and capital costs. The issues the OP raised are entirely valid in the context of her/his specific experience, and it makes no difference whether I agree with those thoughts or not.