It's real sad when you get known even many years after your death, for your utter miserliness. In Islam miserliness is a major sin. It is a great wrong to hoard wealth and count it for the sake of hoarding, to the point where even the person with the wealth does not take benefit. In Islam one must spend their wealth on themselves, their families, and then the excess is to be spent on the wayfarer, the poor, the widows, the orphans, and this is counted as spending in the way of Allah. The giving of zakat and sadaqah, purifies both the wealth and the heart of the person holding it. It combats miserliness, and arrogance due to and caused by wealth.
If mother teresa was a hoarder of wealth, then I too am not impressed. I never was actually. If indeed she held on to the money she got, and did not spend it on the poor she was allegedly helping, then she was not helping at all. In fact in my estimation she hurt only herself. SHe was not doing anything for the pleasure of God but rather to line her pockets or the church or whatever. Her intention comes under immediate question due to her actions, or inaction as it were.