It's highly disputed because the original allegation is not just France, but rather a French-led NATO joint force that included Britain. It's assumed that the British investigation can't be trusted.
The other investigations also doesn't explain the wreckage of a Libyan fighter jet, close to the wreckage of the airliner.
Multiple Italian soldiers were also found guilty of concealing evidence about the event, allegedly by the request of NATO.
Investigations from NATO sources simply cannot be trusted. They are not independent. The only supporters of the bomb scenario left, in Italy, are ultra-right-wing people who refuse to accept the fact that Italian autorities of the time lied.
It was even admitted by the Italian then-PM (later President) Francesco Cossiga, almost 30 years later, that he was told right away it had been a French jet. This was confirmed later by multiple sources, among them a retired US seaman who was stationed on the Saratoga and feared for his life (a lot of key witnesses have died in suspicious circumstances, including suicide). And the secret-war scenario is the only one that can explain a Lybian MIG crashing in the same area on the same day, which was kept hidden for weeks by Italian authorities.
The historical truth has basically been ascertained, it will simply never be admitted by the involved parties because it is still inconvenient (Lybia still being "in play" between France and Italy).
The missing body parts near the front of the plane suspected to be the missile impact point were found.