I heard that coins.ph doesn't deduct fees for transactions, why is that so? How secure is it in comparison to other web bitcoin clients like coinbase or blockchain?
Depends on what cashout option does a user choose. In case of OP, he used Cardless Withdrawals.
Pros: Easy to cashout, no need for ATM cards,
Cons: Some places don't have Security Bank (EgiveCash is only available at this bank)
About cardless withdrawals, thanks Security Bank for having that feature. They have the service like that even prior for coins.ph gained some "quiet" popularity here in PH.