1. Do we know this planet is actually a Federation planet? I thought that the Federation and the indigenous population had to mutually agree on inclusion into the Federation? Since the Federation was meeting the Bak'u for the first time, I think it's safe to assume they were not members of the Federation and neither was the planet. Now maybe the star system was Federation territory, but when they're dealing with pre-warp cultures I think they merely protect the planet and don't own it. That's my impression at least.
2. The Bak'u moved onto their planet over a century prior to the events of Insurrection (am I right on that timeline?). The Federation seemed unaware of their particular area of the quadrant, not having their ships retrofitted for the briar patch. They had no knowledge of the metaphasic radiation, the Bak'u, the properties of the briar patch, etc. before this mission. So how can you say that the Federation own this planet and the Bak'u are merely squatters when in reality the Bak'u had been there for over a century and the Federation knew nothing about it? I think the Bak'u pretty much own the planet. If they don't want to share their technology, then they don't have to.