It leads to a group slug/burn-y playstyle that has great colors and constantly adds card advantage- let's face it, 90% of players will feel that discarding a card feels worse than giving you one, regardless of how untrue that may be
As far as changes to make to the budget build of Mono-White Taxes, I'm actually pretty happy with how the deck turned out
Ugin, Eye of the Storms (Showcase) - $76.69 I own a non-Showcase version of Ugin, Eye of the Storms , and its a ridiculously fun Planeswalker for colorless decks owing to its ability to add three colorless mana at no cost
You cannot force a combination like the above to work out, but you can increase your odds of it happening by taking a broad range of inspiration and trying a bunch of different brews.
while this one is cheaper in terms of mana, it only discounts colourless spells that are 7 converted mana cost (CMC) or higher