For the record, I disagree with you both and this narrative is also part of the problem in my book. Screw the futurism and longermism of "we need nuclear power for space exploration". We're not talking about that. We're talking about mitigating runaway climate effects and filling the blanks of an alternate energy mix by using complementary tech.
Absolutely let's keep working on nuclear power. Absolutely let's keep working on battery storage, and potential energy storage and thermal storage and wind and geothermal and whatever else we can come up with. And absolutely let's abandon whatever doesn't work or is made obsolete, starting with no longer burning hydrocarbons as soon as we can stop.
There's this air of erudite dilettantism about this chatter that just pisses me off. People sitting by and idly projecting their sci-fi fantasies about colonizing planets or about a fully solar powered planet and feeling smart about it. Given the short-term, impending human cost of this issue, both for climate reasons and for energy scarcity reasons, that just feels gross at this point.