I agree with you, but I was not talking only about Electrum wallet and rather had in mind a much bigger picture. What I mean is that we should try to inform people (best we could) to develop a habit, to check every signature of the downloaded file using PGP, especially when it goes to programs with sensible data, but not only of course.
I agree that would be ideal, but the chances of 100% of users checking 100% of the time is 0%. People should also always be checking the URL of the page they are entering their details in to, they should be checking the sending address of the email claiming to be from their bank, they should be scanning every file they download for malware, they should be double checking the sending address they just copy pasted, and so forth. Unfortunately, most people don't pay any attention to basic security and safety measures until they have already fallen victim.
It's for these reasons that banks keep implementing more and more security steps you have to go through and hurdles you have to jump to be allowed to spend your own money. People who pay no attention and keep getting scammed make the system worse for the rest of us. As bob123 says, we do have an issue with wallets being too complicated for the average person, whose only tech knowledge is how to post selfies on social media.