They are trying to entice new and f2p players into buying gems. But let me see if I get this correct.
First time players get a 20% discount but normally before there has always been sales of 40%, so why in the world would I take a 20 % discount for a reward of 3 FB? The 40% was the best deal.

So I believe they are testing the waters by not offering any sales. They are gauging whether they will truly loss money or if they will break even or make a profit. The full price of the gems are crazy high, but for every one that gets sold equals to almost 2 on the 40% off. They believe that DF will get people to spend more. Look at what they did, lower the price of chests while taking away all the extra FB and guarantee epic +.

I truly believe the holiday packs will go back to the norm, where they only offer them on holidays.

The only way to have them change anything, if the majority of spenders stop spending. Yet that will never be case, since there will always someone that step up and spend.