There's a difference between going to a goblin camp for a reason (which happens to be self-preservation) and touching a random dangerous looking thing for no apparent reason.
And if that "Slightly dangerous" thing happened to lead to self-preservation?
Honestly, such logic of not touching a random "Slightly dangerous" looking thing for "No apparent reason" precludes a lot of things in the game.
Blood of Lathander? That looks dangerous, ominously floating there in its pedestal with bunches of defenses before it.
The random switch that opens the area where Withers is? That could be dangerous and there's no reason to push it.
Absorbing power from tadpoles? Literally told by people it's dangerous. No reason to do it (Depending on how much you believe random dream visitor).
Activating the Grymforge? Is explicitly mentioned to be dangerous. No reason to do it.
Etc.
The fact that there's "No apparent reason" to do so gives way to "No apparent reason" to not do so. Yes, it *Looks* slightly dangerous, but that's why it's prudent to find out more about it (If at the very least, to stop it from becoming MORE dangerous. Like what if ignoring the portal caused it to expand? What if it opened a gateway to another realm like Avernus?).
It's also not like you have to jump head first into the portal, you just touch the sigil (Not the swirling, dangerous looking magical vortex coming from it). Which then causes Gale to stick his arm out and ask for help (At which point you have the option to deal with the portal itself using magic, ignore it or just pull Gale out)
In terms of apparent danger, what you do is very low on the list before figuring out about Gale. The game is not very discouraging about it with the single prompt to touch the sigil or not, with no visible signs of actual danger (If all the goblin corpses from down the road were instead strewn before the portal, then it would be a more convincing danger for example) and no build up of unease within characters whom are driven by self preservation (There's a single comment about the portal upon walking up to it)
If with all this, someone still thinks it's far too dangerous to interact with... Then having Gale yell for help beforehand would not change anything. Lest they think that saving Gale is too dangerous too (Which it could be considering the bomb inside him) especially given the situation where you still don't know anything about the portal malfunction, who Gale is, what happened to cause the malfunction (Was Gale trying to do something evil? Is he simply trying to lure you into a trap? Is he simply an illusion made by a Mind Flayer or Devil to cause you to release them? etc)