Because $10,000 is still way too expensive, especially now that there are so many altcoins with the same functionality.  Keep in mind that Bitcoin went from $200 to $10,000 and very few fundamentals have changed between 2014 and 2018.  No one has been able to demonstrate a justification for this rise beyond mania and FOMO.  Be thankful that it's at $10,000.  Don't be surprised when it falls back under $1,000.