I think the article makes it clear that SpaceX does not care much about security here. It's more that they don't have (engineering) bandwidth to actually put something together and sell/support it.
Focus is a very real thing in business, starting an additional product that has a minimal overhead can still end up ~2-3 years later as a massive cash drain with a complex hierarchy of workers with a very small ARR. That's why you take on customers before building it.
The one note I will mention about SpaceX and caring about HW/terminal security is the subsidized cost. SpaceX is retailing the terminal I bought for $500, while I understand the hardware all-in is north of $2000.
In these scenarios you will usually see the vendor default to locking down the platform/hardware, if for nothing else to prevent people from buying it and re-purposing it due to subsidized components included.
Focus is a very real thing in business, starting an additional product that has a minimal overhead can still end up ~2-3 years later as a massive cash drain with a complex hierarchy of workers with a very small ARR. That's why you take on customers before building it.