Is this shirt really that offensive as people seem to take it as?

Hi, so I really enjoy this video game called destiny 2, and recently they came out with an event where one the most iconic guns from destiny 1 will be put into destiny 2. Anyways if you complete the event, you can get a code where you can buy a cool shirt online for about 20-30$. This shirts back is just the logo of the game, and the sides have a cool design, nothing that important, but the front is the controversial part because it shows the gun crossing with the same gun forming like the letter X. Under it has the message “you’re until the last flame dies and all words have been spoken”. I think I described it well, if you need to, look up destiny 2 last word shirt. I asked my mom if she thinks it would look good on me, and she said It would be she says that she won’t allow me to buy the shirt( my money) because of the gun, she said she will not allow such shirt in the house. I said that’s fine and left the room, but I just want to know is it really that offensive to have a gun on a shirt even though it is not depicting any inappropriate message?