Zoidberg: I always find it strange when games' price gets modified, it's like recognizing it was badly priced at first.
Khudos to SHovel Knight's dev for sticking to their work. :P
Maybe it was badly priced at first? Basically, creating another copy of a digital game costs nil, so it's a matter of making as many people buy it for as high a price as possible. The higher the price, the fewer the people who are willing to buy it; whereas the lower the price, the less profit is made per game purchase. Finding the right balance is key, but there is no way to be sure that one has found the golden price point. Maybe most buyers would have been willing to pay a bit more resulting in even more profit, or perhaps lowering the price point would have resulted in sufficiently more sales to more than make up for the loss in per sale profit.*
Shovel Knight is in quite another situation, as the game sold like gangbusters, and thus its easy for them to sit on their high horse(-s ?) and say that one shouldn't cheapen the value of ones game by lowering the price. When push comes to shove, however, either one has to lower the price (or increase the discounts during sales) and hope for an increase in sales, or one may go bust. Then one can try to convince ones landlord to accept ones excess pride as rent.
* As a bit of an aside, the best thing to do (to maximise profit) is to divide ones customers based on willingness to pay and have them pay as close to the maximum of what their willing to pay as possible. Enter the various "editions" where, for some added extra (basically, from a production cost point of view, worthless crap), you have to pay more, so that people with a higher willingness to pay/deeper pockets spend more moolah on what is by and large the same product. Then you can get to the cheapskates pockets during sales, or further down the line, by lowering the price of the product.