Read your own link... immediately following the assasination, Lehi (the militant group in question) was forcibly disarmed and dismantled. If only the PA would do the same with Hamas. The day the Palestinians have their own Altalena (http://en.wikipedia.org/wiki/Altalena), choose to centralize their authority, and reject terrorism is the day negotiations should begin, and not a day sooner.
This of course doesn't even consider the other big caveat to your point... Bernadotte saved Western European nationals (starting in May '45, when the biggest threat was friendly fire from Allied bombing) , a very few of which happened to be Jews, and he did nothing to save the vast majority of concentration camp victims, who were Eastern European Jews, and who were left in the DP camps, with nowhere to run. Nor of course, the complete utter failure of the Red Cross (of which he was the Swedish VP) to monitor and publicize the atrocities in the camps during the war.