>Isn't doing something regardless of potential consequences just another way to define desperate?

No, it is not. If you give a speech in front of a crowd you may embarrass yourself. Are you desperate to give that speech because there are potential consequences? If you go rock climbing you might fall and break your leg. Are you desperate to go rock climbing, simply because it involves risk? I don't see the logic at all.

You might be conflating the proximate and root causes of the act. I may not get in front of a crowd because I'm desperate to give a speech, but I may be desperate to keep my job, or desperate for status, or something else. Likewise, with rock-climbing, maybe I'm desperate for an adrenaline high or a novel experience. To be generous to the OP, I think "desperate" just means the gains from the experience outpace the perceived risks.

This is more aligned with what I poorly expressed, thanks.

desperate: Having lost all hope; despairing.

It's just the wrong word, then, by a huge margin.

In such discussions, its usually better to strive to understand what the commenter actually meant rather than being pedantically correct. The OP clarified their point.

desperate: needing or wanting something very much (Cambridge Dictionary)

There's multiple definitions

I think you actually make a good point for rock climbing being a desperate act. Most humans don't climb rocks. Whether out of complacency or fear, that feels pretty rational! Some choose to ignore the risks. Desperate for adventure, perhaps?

I don't give speeches to large crowds either, that sounds hella stressful. That won't stop me, but I'd have to be desperate for the respect or attention.

Of course it isn’t. If a law is idiotic then breaking it can either be an act of rebellion or just outright contempt