Of course you don't HAVE to infuse, but I bet you had a whole bunch of ugly armor with random useless perks on it. People don't want to play like that. I can also walk around my neighborhood with my pants on my head and bare feet, but that doesn't mean it's the preferred method of travel. You're the one making excuses for Bungie. It's not a question of "are you able to level up" it's a question of "are you enjoying the way you're accomplishing your leveling"