PLA is not water soluble (That's PVA). And works outdoor fine, it just has a low glass-transition temperature where it won't work very well in high heat areas.
(counter-third) Cura doesn't gives a rat's ass about your surface normal. And the upcoming AMF standard support curved triangles to solve the millions of tiny faces problem.
I'm sad to hear that you own a Makerbot. I got an Ultimaker a year ago. And now I'm working at Ultimaker for a few months on software developement. We leave Ultimakers unattended a lot. I've added extra safety features in the RepRap firmware for this reason. We've done 100+ hour successful prints on our larger sized printers (up to 52cm). And we're working on improving the safety on our ready-build printers. But I have no fear in leaving our printers run unattended right now.
Makerbot does little innovation and mostly marketing. PLA printing? Guess who started that. The Makerbot extruder? copy of the UP! extruder. Gantry system? Ultimaker started with that. 3D scanner? Makerbot already did that in 2010 but they erased most traces of it.
As for the filament price. I know a raw roll of 0.75kg PLA costs us about 20 euros in bulk. The producer of the filament pays 4-5 euro's for the raw pallets, but has done a 20k investment for the extruder, and numerous hours tweaking the production process. So the producer needs to sell 1333 rolls before breaking even at the current price. The reseller also makes some profit for splitting the bulk into single rolls and shipping them. Add some tax and you are at the 30 euro price (which is 40 dollar, your factor is slightly off because I mixed euros with dollars)
In pure solid modeling FOSS we have FreeCAD and OpenSCAD.
Blender has some help tools for solid modeling (the "select none-manifold edges" [ctrl]+[shift]+[alt]+[m] really helps, as well as the remove duplicate vertexes with a range setting)
Board gamers love 3D printers for custom play pieces.
Lego builders like them for custom bits.
Robot builders like them for getting that missing bracket/piece now instead of in 2 weeks for 10x the money.
Architects like them for scale models.
Product developers like them for prototypes.
Artists like them to produce new and interesting art.
And I like them, because I'm printing an Desert Eagle for an arcade cabinet.
(Actually printing a working gun that does not have the risk to blow up in your face will be proven to be quite difficult)
You sir. Sorry for the word. Are an idiot. And have no idea what you are talking about.
A kg of filament is a LOT of filament. Plastic is light and objects are printed partially hollow. I do expect prices to drop a bit in a few years, as the raw plastics pellets costs about 4-5 euro per kg. (asking for 40kg per dollar is just sticking your head up your ass and asking for a pony)
Great for programmers, sucks for average humans. (And well known within the 3D printing communities. It's the 2nd most uploaded file on thingiverse, next to stl)
I made Marlin Arduino 1.xx compatible a year ago. And everything you say is RepRap related (who do a bad job at documentation), not 3D printing in general. You can buy an Ultimaker kit and be printing within a day. But you went the DIY route and are now surprised that you need to DIY stuff...
Stop looking at the bad reprap prints, and look at this:
All done on stock 1200 euro Ultimakers.
A 30 day old character doesn't have the required skills for a Vindicator.
Not sure how you could build a $200 3D printer. I did a BOM for my TITAN 3D printer. And I'm on about 300 euros. Just steppers and steppermotor drivers sets you back 100 euro. Leaving a 100 for hotend, rods, bearings, and all other parts...
PLA is a lot of things, but soft it's not. It bends less then ABS before breaking. But it is very strong.
Support structures is quite a standard feature, but they leave ugly scars on the models.
(I work at Ultimaker, and we print with PLA 99% of the time, as it doesn't stink and prints nicer)
He bought it as DIY kit, we've been only selling the pre-assembleds for a few weeks. And only a few have shipped so far. We are open source. AGPL with the software, GPL with the electronics, and CC BY-NC with the mechanical drawings.
There is no offical heated bed yet, but people have build their own, as the electronics are prepared for it. Same for dual extrusion.
Disclaimer: I now work for Ultimaker. After developing FOSS software for the Ultimaker they hired me as full-time developer so I could spend more time on making the software even better.
There are more keys in use then just for HTTPS.
If you want to feel this kind of control yourself, try the Kerbal Space Program.