You can't destroy bitcoin by selling fake money to gullible people. Bitcoin simply doesn't care.
Keep in mind that bitcoin is also not like other things like fiat or gold for example. You can't store either of them on your own so you need a centralized third party, then they turn into fractional reserve. But you can always store bitcoin on your own no matter the amount. So these services are already unnecessary.

There is a hype about them right now because bitcoin is being seen more and more as an investment and newcomers coming from the "old world" don't yet know they don't need third parties.