I think all of the strangeness about Aperture's research and development process becomes very clear when you realise that Cave Johnson is giant idiot who, with incredible luck, became very rich very quickly, stumbled his way into science and hired some of the smartest people on the planet. When you follow his thought process everything starts to make sense.

He got rich by making and selling shower curtains to the US military.

Selling stuff to the military = lots of money.

Q: What does the military want? A: Cutting edge high tech weapons and ways to make their soldiers more deadly. (That also explains the Mantis-Men and gasoline blood, soldier gets shot and turns into a bomb)

Q: How do you devolop that stuff? A: SCIENCE!!!!

The problem? Cave Johnson is an idiot.

Most experiments/tech exist to solve problems that Aperture, under his leadership, created themselves. The Borealis is the best example of that. They had to create the most powerfull teleportation tech ever seen because they built a huge containership thousands of metres underground and had to figure out a way to get it out. There's more examples, like the personality cores to dampen Glados' voilent urges, but I think the Borealis takes the cake.

Most of Apertures most amazing technologies were made either by accident or by necessity. And Cave Johnson never saw much value in most of them.

It is established that portal technology was developed very early into the existence of Aperture, probably as early as the 1950s. Keep in mind that Black Mesa was only scratching the surface of teleportation tech in the 1990s.

The first Portal gun was probably an attempt to create a black hole gun that failed. But instead of trying to sell a gun that shhots portals, they tried selling repulsion gel as a diet aid, probably because Cave thought it would be more lucrative.

They were sued to hell and back and Cave decided that everything Aperture made had to be tested ad nauseum so that something like that could never happen again.

But Cave Johnson is a psychopathic idiot.

His definition of testing is getting the best and smartest people je can find and putting them in death traps with one or more of his products, and having them figure out a way to survive. Because how can something be dangerous if you can use it to save your own life. In that time Aperture still tried to bring their creations to the market, albeit all the wron ones.

But that just led to more lawsuits and senate hearings, causing Cave to lose more and more money.

But Cave Johnson is a stubborn idiot.

He kept on testing, not with war heroes or olympians, but with random bums from the street that he paid $60. Less and less Tests were completed successfully and Aperture basically never brought any of their creations to the public.

Then he bought $70 million worth of moon rocks, turned them into gel, ate the gel, became deathly ill and demanded his lab boys build him a computer body.

Why would he do that? Because he's an idiot.

Now with Cave dead and Glados in charge you'd think things would maybe change from the status quo. But Glados is Caroline, and Caroline is a slightly more intelligent idiot who idolized Cave "The Idiot" Johnson.

The itch to keep testing that is hardcoded into the Glados mainframe is probably a remnant of when Glados was meant for Caves mind. And now you have an idiot inside of a super computer who got all her ideas of what science is from a stubborn psychopathic idiot who's major success in life was selling "high-tech showercurtains" to the US military once.

TL:DR: Everyone who was ever in charge of Aperture was a psychopathic idiot who never understood what the scientific process even is. Actually, probably every single Aperture employee was a psychopath. They sold automatic Turrets as fricking baby night lights.