The same reason people don't talk about it in real life. People don't know what it is and it's effect on value, especially when conflated with the word 'interest'
Inflation means a somewhat different aspect, that of more coins appearing. Bitcoin suffers from POW-Inflation means that there isn't only more coins each day, but Market Cap loosing that same amount payable upfront to wall socket power suppliers in hard cash.
Market Cap: $ 5,407,695,423
Bitcoin $ 4,841,874,395
---------------------------------------------------
all Alts together $565,821,028
that is 89.5% of the whole story pulled by Bitcoin allone.
"Crypto is going down" due to electricity costs for POW mining, which are on a ROI of ~10% for Miners easily calculateable. Let us just hope they experience a ROI, otherwise hashrate will inflate quickly.
Think of all the miners having to pay 90% for electricity & production hardware, today that was $ 1,156,680 or 0.02% a day. Summs up over the year but stays in total nearby 7%
(if they have to pay 110% and are mining on a loss, figures get worser)
So why do we have had that $ 315 all-year-low for 1 BTC ?!
There are two effects, the first technical one is POW-Inflation so bleeding money to electricity companys, but the even bigger must be a lack of interest by Joe Average out there. Market adaption does not happen. POS could trigger that interest of Joe, but the total percentage % of POS on Total Market Cap is currently negligible.