That's not the problem; since it has not a battery and you need to load the seed every time, having a secure element would be pointless.
SeedSigner is a *great* tool, but it is not immune to the attack described in the article, you you must be careful about the software you are running. A basic precaution is not to leave the microSD inserted, so that an attacker cannot simply overwrite it and let you run a tampered version.
Fair point. But it's all about tradeoffs to me. Purpose built hardware (like hardware wallets) = more prominent targets. Generic hardware = more responsability on the user to verify the software manually