"Send another robot!"
Could that happen?
The orbital mechanics around Lagrange points are weird.
Or to 1997, and telling Goddard "Your specs will require technological development that we feel should be halted until a commercial spaceflight program develops. We're pretty sure next year someone will found a e-commerce business that will make him a billionaire, and he'll sort it all out."
Or to 2002, when tech internet tech was booming and paypal was going IPO, to tell TRW that the $824 million they just acquired should be put on a shelf until about 20 years later.
Or to 2005, 12 years before BFR was announced, when it appeared cost growth was a factor (not at all related to northrup aquisitions). Again, 2010 it passed review, 7 years before announcement. Is it really irony or somehow a waste? I don't think so.
(Full disclosure: I'm working on alternative tech to deoployables for large-aperture telescopes, but I greatly appreciate their efforts on JWST, given what we had over the last 20 years).
"So what if it fails? There's a lot of money sunk into that! Well, maybe someone would actually decide it's worth going to the L2 to fix it, wouldn't that be cool!!"
So yeah, not the only idiot...