How the Deluxe version made Transport Tycoon immortal

Transport Tycoon Deluxe is a game I've installed in some fashion on every PC I've owned in the 30 years since it came out. But what makes this Deluxe version, something that should be little more than one of those mid-'90s publisher cash-grab special editions, so much more compelling than the 1994 original?

The tiny thing that happens when you click on the same signal twice.

Find out how this one seemingly small change is emblematic of the philosophy which drives Deluxe, and how it made it one of the most enduring and playable management games of the mid-1990s.

Pathfinder decisions:

0:00 Twelve seconds of controversy
0:50 Microprose's hasty sequels
2:39 But it's... done?
4:20 Early disappointment
5:57 Let's talk signals
7:06 Megarail, 1960
8:57 The bit which starts with the dog running around
10:33 Going back to 1960
11:33 Going back to 1994
12:36 Not going back to 1930
15:58 A linguistic diversion
16:41 Terror from the extra deeps
18:39 How to draw your own conclusions
20:33 My personal PC context
21:58 Unnecessary Britpop
23:28 It's that train set again

Bonus fact: something about x86 assembler, probably.