There is clearly no intention by most MPs to leave the EU, but they do not want to take the responsibility for setting aside the "once in a generation" Referendum result.
A 2nd referendum would not solve anything. If the country votes Leave again, we are no further forward. If it votes Remain, then the Leave voters would demand a 3rd, deciding, referendum. MPs need to either honour the referendum result now, or be honest enough to state that they refuse to leave the EU, and revoke Article 50. Neither option will harm the country more than the current uncertainty.