The B777 has been flying for nearly 19 years. And therefore could be regarded as a fairly mature design. It's safety record is excellent, with few incidents directly attributable to the aircraft. There is a huge knowledge base out there of thousands of pilots with years of experience operating all over the world.
Surely by now any inherent faults would be known about and either corrected, or the pilots trained to deal with them.
Airbus had a number of incidents when the A320 was first introduced but that type was radically different from anything previously flown. Some design changes were made and training improved as operational experience grew. Today it's safety record is excellent, especially given that it operates multiple sectors per day into secondary airports with less experienced crews. The B737 also has an excellent record in the same operational environment as the A320 but relied on older, tried and proven technology rather than cutting edge new design.
When the final report comes out it's likely to show that once again the weak link in the safety chain is the human interface with the automation together with the age old "if it can go wrong, it will go wrong."