I think most of the educational value is gained from having access to a microscope, not having each child able to build one. A teacher who builds one in class with the kids watching and then selects a useful slide and projects it on a wall will likely get you 95% of the benefit. "Look at this unboiled water vs this boiled water".
I didn't have to build my microscope at school but it was still educational to have access to one. This is primarily for kids that don't have what we had. (At least from an educational perspective - the medical perspective is arguably more important.)
Too bad that thing is unmanned. For sure, it massively reduces the complexity (no life support, no need for high-temperature-stable glass, more agility in flight due to much higher g-force tolerances)... but just imagine flying it!
At one point CheckPoint VPN didn't support 8.1, now it does. One of my customers uses it so I held off upgrading. There could well be other apps with similar issues and big corporates would prefer others discover them.
Facebook needs to charge different click prices depending on the quality of the profile. clicks from 10-friend profiles that are only a year old and like every page they hit, aren't as valuable as clicks from profiles that are more organic and have been around for years.
Opportunity had a planned 90-sol mission duration but continues to be useful. Maybe there isn't any useful task this bird could be used for, but I'd be surprised if the wider scientific community can't think up anything.
It's great advice not to be that type of asshole when you've done nothing, but it's also true that one of the pillars of YC success is someone who doesn't necessarily know your niche telling you what you're doing right/wrong.
Sometimes advice is about the niche, sometimes it's about time management, time-to-market, hiring, firing, whatever. The answer has to be about balance - sometimes you know better, sometimes you don't.
Damn, a customer. One of my final school projects in '91 was a text drawing program. Using it, I was amazed what effects I could get with text, background and foreground colours. Amongst other things it had line drawing, box fill with fg or bg colour.