Some people might be fine with the auto aim being taken out, could be because, like you, they like that it increases the skill required, the auto aim could sometimes actually throw off their aim, or some play the game on a computer, so the change doesn't affect them that much. For those that are fine with that, all of those issues could be addressed to an extent by adding in an option to turn off auto aim on an EM rifle, that way the players who don't want it can play it that way. For many others who purchased the EM rifle, they bought it for what it was, including the auto aim, and many of them also aren't playing the game to try to be a pro or top ranked player, it's meant to be a relaxing time killer with a bit of a challenge. Sure, removing auto aim adds in an additional challenge, but that addition might be more than casual players are looking to deal with when relaxing.
If they wanted to remove the auto aim, then they should've also removed the shot delay and laser sight. Don't let your targets know that you're about to fire on them with a telegraphed shot. Make it like every other sniper weapon that doesn't have auto aim and fire immediately. I'm sure there are players out there who can keep their shot lined up through the delay, or can read where their shot will need to be at the end of the delay, but there's also people who when they press the fire button, they're looking at where the shot is, not where it will be, and the auto aim made up for that.
With the damage change, if auto aim is left off, I'd say they should either decrease the reload time, or add one additional shot to the magazine. If not one of those two, and they intend to leave the shot delayed, then they should actually increase the damage, just don't allow bots to use it. It's going to be a more difficult weapon for players to use, less accurate without auto aim, and a missed shot can make or break you with the one shot magazine and reload, so make it so that one shot is actually worthwhile. I would say either way, if they want to leave the shot delayed with no auto aim, then they should be refunding or compensating people for purchasing it, as it was a major feature that was a part of the draw of the weapon and they took it away.