Honestly this depends on the situation, and while yes, some situations/problems are only temporary, some just aren't. It's insensitive.
Will have to channel what you said.
Suicide is a pretty murky thing and not everyone whose considering it should maybe go through with it. Especially folks with unstable mood disorders like bipolar or borderline, they might want to really take the time and space to make sure it's a right fit for them. Obviously if you're in your rational mind and you can see that constant ups and downs aren't sustainable and medication is either non-functional or not an option, then sure. But in a lot of cases, and especially with more impulsive people, it might not be a terribly good idea.
That said people have a right to do things. We don't make a law against gambling for impulsive morons, we just kind of try to advise them not to but they'll do it if they want to. There's also just the fact that for some suicide is a reasonable option but that invites a level of gatekeeping and I don't want to gatekeep the right to die. Ultimately people have freedoms and those freedoms include self-annihilation, and that's just a fact of life, no matter what some pro-lifer moron has to whinge about it.
And also, half the time it's not even coming from that well thought out of a place. Sure some people might have "temporary problems" but the person who says this never thinks about those problems in those ways and weighs whether they are rationally "temporary" or "permanent", they just assume that suicide is such an unreasonable and awful horrible no good very bad thing that the person who considers it must have something
wrong with them, and people who have things wrong with them shouldn't get to make their own decisions in life anyhow, right? So ultimately a form of abuse, both infantilization and condescension, as though most suicidal people aren't a) adults and b) put some thought into it and have been trying for quite some time.