From a purely strategic perspective, as in military doctrine or game theory, expanding your set of viable options is almost always advantageous.
The goal is to maximize your own optionality while reducing your opponent's.
The failure mode you're describing isn't having options, but the paralysis of refusing to commit to one for execution.
A better model might be a cycle:
Strategy Phase: Actively broaden your options. Explore potential cities, business models, partners. This is reconnaissance.
Execution Phase: Choose the most promising option and commit fully. This is where your point about the power of constraints shines. You go all-in.
The Backlog: The other options aren't discarded; they're put in a strategic backlog. You don't burn the bridges.
You re-evaluate only when you hit a major "strategic bifurcation point" - a market shift, a major life event, a completed project. Then you might pull an option from the backlog.
This way, you get the power of constraints without the fragility of having never considered alternatives.