Is flexibility good? That is a loaded question, and I know it. Flexibility might be good in some situations, and bad in others. One place where it is bad is the rules for Mass. Basically, the rules for every form of the Mass are fairly clear and quite strict. Yet, in all of them, the modern Novus Ordo has more places of "flexibility" and "options" than any of the others, and that leads to many of the serious problems that we see today.
Our own spirituality is the same. Do we see things are entirely flexible and optional? Or, do we see things are generally clear and strict with a small amount of flexibility that allows for different individuals to acknowledge their individual callings? The latter is what the Church advocates in many and various places. If we allow for too many "options" in our spiritual lives, then we will always tend to choose the easiest and least helpful options (just like so many priests do in the Novus Ordo).
You have options for what time to go to Mass, but you do not have an option about whether to attend a Holy Day of Obligation. You have flexibility about what form of devotion you may use in your prayers, but you do not have flexibility about whether you should pray or not. This is how we each should see ourselves before God, and we should seek to know how best to be obedient to what we are required to do.
We are vertebrates, and if we live our spiritual lives like jellyfish the results are not going to be good. A spine can move but only so far before it breaks. We have room for movement in the Catholic faith, but if we "move" too much, we will "break something" in our souls, and end up outside the faith.