Hoarding (saving) is actually a good thing. It's what gives a currency its value. If everyone is always spending their money, the money becomes worthless because nobody wants it. So the goal should be to get more people to save, because that increases the depth of the Bitcoin markets, and allows more capital (read: value) to flow through them. Currently the Bitcoin markets are actually rather shallow. They only allow a dozen million dollars' worth of value to flow through per day. With more hoarding, that number can skyrocket to billions of dollars per day. Of course, like I said, you shouldn't hoard 100% of it obviously.
You actually have this backwards. If no one spends any bitcoin then there is nothing that would give it any value. There is no reason why everyone would want to buy bitcoin for the sole purpose of it increasing in value.
If there is a vibrant bitcoin related economy on the other hand then people will buy bitcoin with the intention of being able to spend it with lower costs then if they had spent money in other ways (via credit card or WU for example)