Hmm, I prefer the phrasing:
In theory, there is no difference between theory and practice. But in practice, there is a difference.
Mine is intentionally convoluted. It works for two things: 1- Easy to spot people who really aren't paying attention to what you say. 2- It takes a second to understand the point, people remember better when they have to 'figure it out' so to speak. 3- I get a smile from some people if they pause, think it, then understand.
I might be wrong in my assumptions though.
https://www.snopes.com/fact-check/practice-and-theory/
This "practice and theory" quote was said by someone, but who exactly said it first was lost to time. Its not going to be possible to find the canonical quote (since the cannon-quote seems to be nonexistant). But its definitely a long-running idiom with some history.
When I said 'mine'/'yours' I simply meant what we use.
I tend to presume that originality is near impossible with such pithy sentences. For quotes, I only quote things I actually read from the author.
As a pragmatist, one of my favorite phrases I say quite often: "The difference between theory and reality is that in theory there is no difference."
The article is excellent expose of an issue and a solution. I hope they would include specific things we can do to help improve the situation. I'm part of California YIMBY, which promotes legislation that helps ease these issues.