Donald Tusk explained why.

Poland currently has no intention of transferring additional Patriot missiles to Ukraine. This was stated by Prime Minister Donald Tusk after a meeting of the leaders of the "coalition of the willing" in Paris, writes UNIAN with reference to rp.pl.
Tusk stated that Poland "does not have large stocks" of these missiles.
"You also noticed the resonance caused by our decision to transfer five Patriot missiles, fully agreed with NATO and the Americans… We are not planning such a donation yet," he stated.
The Prime Minister of Poland also stated that he does not expect a quick end to the war and that escalation will continue at least until winter.
At the same time, Tusk emphasized that as long as he remains prime minister, Poland will actively participate in assisting Ukraine in its fight against Russia.
Answering a question why Poland did not join the antiballistic coalition of European countries together with Ukraine, Tusk said that Polish companies are currently assessing their capabilities.
"The coalition is open; when an industrial offer from Polish companies is ready, we will join this coalition," the Prime Minister stated.
Comments
Таму я лічу, што ракетамі Украіне ў першую чаргу павінны дапамагаць тыя краіны, якія не знаходзяцца на першай (пасля Украіны) лініі наступнага ўдару Расеі. Тыя, якія нічым не рызыкуюць - Германія, Францыя і гэтак далей.
Бот "Ганьба", "Ваша дарагая", "Сама сыдзеш", "Разам" і г.д.