I'm seeing a lot of people with very similar criticisms of the Pathfinders across the board here. Personally, I've only played a handful of games, but I can see where this is coming from based on my limited experience and how things look on paper. I've observed three, and played three, outside of a campaign framework. Currently I'm 0-3; in the latter two I was put in the defender role in both Raid and Ambush missions (against five power armored CSM, and a six man GSCult team), and I was starting to feel the issues I'm seeing here.
I suggest that, for those interested, you make a post on the Warhammer 40,000 facebook page
with this feedback. Making respectful and concise criticism may go a long way to seeing some of these issues fixed in the upcoming (or other subsequent) rules releases.
However, keep in mind some of GW's practices and the framework of the kill teams before recommending solutions. For example, I see lots of people in this thread clamoring for rules to take pulse rifles on pathfinders--this is probably not going to happen. Not only are pulse rifles not in the pathfinder kit (kit contents being a major factor in the makeup of the rules), but it isn't thematic to the lore of pathfinders as per the codex. Instead, comments regarding tweaking the rules of the carbines themselves might be more helpful—adding sustained fire 1, or a +1 to hit in a range band being useful suggestions.
I made a post myself regarding some of the glaring omissions in relation to lore; the lack of jetpack movement for our stealthsuit and drones, lack of representation for the underslung photon grenade launcher, and the copy/paste job for the ion rifle that also lacks a secondary blast fire (it would make a perfect tau version of the grenade launcher). But this feedback was prior to playing many (any?) games.
Ultimately, post your feedback there as you would here. Perhaps if our community (both the Tau and ATT) get a good reputation for providing valuable and respectful feedback, we might be looked at for development and FAQs for the faction in the future