So do collectors. When LRG puts their games up for sale for example, and they are limited to 2 per person, and someone buys two - one to open and one to keep sealed, that is making it harder for someone out there to get their hands on a copy of the game.
I'm not saying it's wrong. They are letting anyone buy 2 copies, so you can buy 2 copies, but for every disappointed person when they miss out on a game and see copies on ebay and are like "Damn, I missed out and now I gotta pay $X.XX on ebay!", there is also a disappointed person who is like "Damn, I couldn't get a copy in time, and there are a ton of people out there who have copies of these games on their shelves and they aren't even gonna use em, they are just gonna sit there on a shelf!"
I think society has conditioned us to think one is better morally than the other, but I really don't think there is anything wrong with either, and while the road to get there is different, the "destination" of both scenarios is gamers who want to buy games and play them are not going to be able to because someone bought them for purposes other than opening them and using them.
I personally collect games, and I have some sealed games, although not a ton of them. My only sealed games are ones I really have an affinity for. But I must admit there have been times where I bought rare games on ebay for a markup and I was thankful that those resellers put them on ebay because without them, and if they had gone to collectors instead, I would have not been able to get my hands on them at all. So I can speak personally to where both methods are something that ended up being a positive for me.