Its a kick in the teeth to many that bought Horizons thinking that their rig that runs the base game would run the expansion too.
I dont really agree to that part. IMHO you always have to expect, that an addon raises the specs because addons bring new features and new features often needs more processing power. If an addon runs with the same specs as a base game than it is pure luck from my point of view. But yes, it would be better to make that clear more early. On the other hand I find the term "countless many" greatly exaggerated, I really doubt the number is that high. The minimum specs are still quite low so it wont expect, that FD really have to fear a big wave of refund requests.
So you are saying at point of sale for Horizons, devs and FD had no clue of min requirements?
Yes, most likely. To define the specs you have to do optimizations in most cases and these optimizations are done in yery late state of development, where preorders already have started. In todays times, where you develop right until release, specs are always subject to change right until release. If you release them to early than maybe you exclude too many potentional customers if the optimization runs show later, that there i room to lower them. So its quite common today. And this is only problematic if you do not offer refunds for customers, who are affected by these late changes in specs.
I feel otherwise, that this was a marketing move knowing that not 100% of sales that need refunding will not apply for it.
Maybe, but most of the companies I know work that way. Its the job of a marketing division to stretch the truth as far as possible. So I fail to see the problem in this case.