Because context matters, and the context of the comment you replied to was literally "oh, we should just build solar panels on mountainsides which are not good for other types of building": https://news.ycombinator.com/item?id=43254135
So the conversation, in context, is literally this:
---
Someone: we should build panels on mountainsides
Me: how much more expensive will building and maintaining them will be?
You: Maintaining solar panels will be always way, way, waaay cheaper than maintaining nuclear. Also batteries will need to become cheaper
Me: Erm... That doesn't answer my question, and on top of that you're admitting batteries are not cheap either
---
But, again, this is on par with what I expect in such discussions
So the conversation, in context, is literally this:
---
Someone: we should build panels on mountainsides
Me: how much more expensive will building and maintaining them will be?
You: Maintaining solar panels will be always way, way, waaay cheaper than maintaining nuclear. Also batteries will need to become cheaper
Me: Erm... That doesn't answer my question, and on top of that you're admitting batteries are not cheap either
---
But, again, this is on par with what I expect in such discussions