If you think about it...asceticism is another form of ingratitude. We all know that wanting things that you don't have is ingratitude. But not being thankful for the bounty God has blessed you with, and feeling guilty about it, is ingratitude also. In other words, wanting more than you have is ingratitude, and wanting less than you have is ingratitude also.
When we moved a couple of months ago, I was convinced that I had too much stuff! Now granted, some of that stuff was junk and in excess and just needed to be given away or thrown away. But some of it was stuff that was just God's blessing! And rather than despising it, I needed to be grateful for it! Thank you God for the many blessings you have poured out on us! Thank you for the fact that we can fill a 26' truck, and a trailer, and a truck, and a van with all of our stuff, and this just goes to show how very blessed by You we really are!
So branches of Christianity that say that it is the more spiritual thing to have less, and you should feel guilty if you have more, is just ingratitude repackaged. They want you to feel guilty for the gifts God has given you, rather than lifting up hands of thanksgiving to God in good Ecclesiastes fashion!