Assuming these people don't understand that their ideas are unworkable is a mistake. Don't believe for a second they are stupid or ignorant.
The difference between a criminal and a law-abiding citizen isn't that the citizen knows that crimes are wrong, it's that the citizen cares that crimes are wrong and the criminal doesn't.
>they are stupid or ignorant.
Nope, probably the more apt description is 'in denial'.
I think that's very charitable.
I'd describe it as "kayfabe".
Reading the paper they wrote on this from their GitHub site, it does take into account the thermal management aspects quite considerably.
https://starcloudinc.github.io/wp.pdf
Your thinking seems more risk averse, which is similar to myself. However that doesn't mean that without the business drivers these types of things can't happen if enough attention is given too it. Costs are often because we're comparing one thing which has significant efficiencies built into the supply chain, vs something that doesn't, which by virtue drives up the cost. Perhaps Nvidia have money to burn on trying something.
I could be wrong and this will be a slam dunk. To me, however, the costs/complexity (Cooling, SRP perturbation, stationkeeping, rendezvous, etc.) far outweigh the benefits of the Cheap as Free (tm) solar power