ITA has been in existence for less than 4 months, so not much 'history' to go on.
My suspicions, not based on any hard fact research, are
1- The planes are the ones Alitalia used. Some may have the new name painted on them.
2- A lot of the staff are former Alitalia employees
3- too soon to tell if there has been a real cultural change, or just a new name with the debt wiped away.
For a 2 hr flight choosing among the available airlines . for me, would be a matter of schedule and the TOTAL cost.
When I have looked at a 'regular' airline and an 'economy' airline, the initial saving of the 'economy' airline shrinks/disappears once baggage fees, seat selection and whatever else they throw in has been added up.