Why not is because there is Bitcoincore that's free.
3) most people do not trust hardware wallets.
Even when I was aware of it since its existence. I also don't trust HW. Although I haven't heard anyone got hacked or hardware wallet codes are altered, I can't just rely on the words of the company but I do think they are true to thier words in serving Bitcoin holders.
Are the codes of these hardware wallets even open source?