I like the simple definition, too, but it's been pointed out in the many previous threads in which people have debated the definition of "technical" diving that the virtual ceiling (deco obligation) can vary depending on the conservatism setting (e.g., gradient factors) the deco calculation is based on. Is a dive to X depth for Y minutes not a technical dive when the so-called no-deco limit (NDL) is calculated using low conservatism, yet the same dive to X depth for Y minutes becomes a technical dive when the NDL is calculated using higher conservatism? It gets messy. I think trying to nail down a precise definition of "technical" diving is a fools errand.
Is a dive to 131 feet a technical dive?
I'm the kind of person who always seeks clear definitions, bright lines. I'm just not going to find that here.