Its not being given away, either way you have to do something to get it, be it coins or its given as a reward at the end of an activity. Same as glimmer or marks, its an in game currency used on in game items. Strange coins don't come as often as glimmer or marks to a certain extent so that doesn't justify him not selling exotics. RNG works weird for some of everything, I've been playing since beta and I didn't get the thorn bounty until about a week after the dark below dropped and that's just a bounty not even the item. There aren't enough items for the game as is or activities for everyone to not have access to the same opportunities. Not everyone wants to toil for hours on end on 3 characters in one activity hoping to get something. Xur was around pre-raid and no one complained about getting weapons from him then. What's the big deal now? Y'all would have an argument if he was patched in after the vault or dark below but he was here from the start.