Because it's in production and people are using it. When you rewrite a new implementation from scratch and deploy it, you make their lives miserable, because so many things will break. This is nearly inevitable.
When talking about websites and web applications, client-side integration makes it nowadays very easy to add new modules to legacy codebases using a completely different technology. With a little bit of JavaScript, you can have some parts of webpages coming from an entirely different new server, using a new fresh framework and backend database. I think this is the best way to start migrating to new technologies, one step at a time.
Because it's in production and people are using it.
I've run into more examples of broken code for which the above statement is true than I care to remember.
My original response was meant to be a rhetorical question, with the purpose of hinting that techniques for verifying the correctness of code might have existed existed prior to the 1990s. But "we haven't heard any complaints from users yet," while certainly a popular technique, is only slightly more reliable than prayer as a QA policy and I personally wouldn't recommend relying on it.
That's kind of the angle I was coming from as well. In order to effectively rewrite something you first need to know what the existing code actually does. If you don't know that yet, then figuring it out is usually a lot harder than fixing whatever problems it has.
It's not that you should never rewrite, but it's always a lot more work than you think it's going to be.
It's possible to travel for a lot less. If you are on a tight budget. I traveled for 6 month in India, Nepal and Thailand 2 years ago for less than 6k.
Let's be fair: The old green-screen monitors had much larger font sizes. Maybe that was less harsh. Also, I had younger eyes. ;)
Does anyone have an actual Apple II green-screen display (40 or 80 columns, 24 rows) emulated in Javascript to share with us? I found an Apple II emulator but it only plays games.
The shapes on old green-screen monitors were also significantly softer, which I believe helped readability as well. Small, sharp green text on a black background is just killer on the eyes.
OS X defaults to much softer font rendering than most systems, and Windows/Linux can be tweaked (try googling for things like "OS X style font" or "soft font rendering" with the name of your OS tacked on)
If you want a free, git supported web hosting, I highly recommend using Heroku free plan instead.