Ideas that were also present, at one point, in a certain country to the west of Poland that eventually went to war with the Soviet Union (after signing a deal with the Soviet Union to carve up Poland), so it's not as if this behavior is obviously "soviet" or "pro-Russian".
Both the nazi germany and soviet union shared many authoritarian ideas. Still, I believe that's irrelevant to the original subject.
I fully agree that the ideas I mentioned earlier, don't make PiS 'pro-Russian' per se. However, because it is widely said that PiS looks up to the Hungarian and Russian governments for inspiration, some people assume that PiS is pro-Russian. It is not. It just reuses the ideas.
Because those ideas stand against EU ideals, Poland might get alienated and drift in the general direction of Russia, just as Hungary did. No, it won't leave EU or anything like that. But this drift might weaken EU and people's rights in Poland.
The only problem with Ubuntu versus some other offerings like Red Hat is that the support time of the LTS version of Ubuntu is pretty short (only 5 years). It really depends on your project whether this is good enough for your situation. Debian doesn't even have such a LTS version. You only have to guess when Debian stops supporting their OS.
Debian does have LTS support  which means that stable releases are supported for (at least) 5 years. You also don't have to 'guess' anything - EOL dates are also provided at  (and in a few other places).
Pound for pound, the amoeba is the most vicious animal on earth.