Your account is way more secure if you use 2FA.  I recommend enabling it if you still do not have it enabled.  The guy in the link you posted was actually sharing his account with a "friend"

When visiting Bittrex please make sure to bookmark or manually type in https://www.bittrex.com Google currently returns phishing sites as advertisements for Bittrex.  These sites look just like ours and have been tricking users into entering their credentials and multiple 2FA codes which are good for 2minutes.  Typically they have the user enter their code and then tell them logins are congested and to please wait, at which point the user again enters their code.  This means the attacker has entered their account on the first try and then now has a 2FA code to withdrawal for 2 minutes.  Below is an example google search.