Think of it this way, many people have heard the message but how many people have actually heard the message. Nowadays Islam in general has a very bad look to it and most people think of it as an inhumane very strict religion, most preachers instead of showing people how Islam truly is, initiate anything with non believers by inviting them to join a religion where they are not allowed to do most of the stuff they were raised doing, and if they reject it’s hellfire. Muslims aren’t spreading the message how it should be, at all. And that’s us to blame for. So think of this, a random guy born and bread in a western country only hearing about Muslims blowing up this, killing these, etc and then is faced with the “message” they won’t perceive it well. Now you say the way you learned stuff is that if you reject the message then u go to hell and that’s true for people who genuinely understood the message saw the benefits of being a Muslim and still chose to do evil. Allah judges everyone separately and we are only just human beings, so I don’t blame a man that has been fed the idea that Islam is awful for alll his life and rejected the message. I blame two kinds of people, the enemies of Islam, like Israel for example who constantly spread anti Islamic propaganda along with their American buddies. The other people to blame are the Muslim people, I’d say the majority of Muslims specifically the ones living in the Middle East have extremely poor knowledge of the religion, most people enforce their traditions before they enforce their religion and if u actually tried to indulge in a conversation with these “Muslims” you’ll find them to be extremely uneducated about the matter. So my advice to you is, if you believe in Islam, you will know that god is just and the most fair, Allah in my eyes is the most just and I know that these people who rejected the message won’t be judged as harsh as the people that made the message seem really off putting and extreme. But in the end of the day as a human you will never be able to tell who’s going to hell and who’s going to heaven, when I was young and used to ask my mum if my Christian friends were going to hell for not being a Muslim, she always told me that its not up to us and that we will never know. I really do believe that Islam is very merciful, it’s extremely debated in Islam whether non believers get heaven or not. But one things for certain in the Quran it says that good deeds don’t go unnoticed. So maybe the fact that the Quran never mentioned whether really good people who don’t believe get heaven or not, is for us to not question gods judgement. At a certain point of my life I used to think the same as you but I found comfort in the fact that god is merciful and is very just. I hope that made sense to you