At the end of his report on the state of the Dominican Order, Fr. Carlos Azpiroz Costa, OP, Master of the Order, mentions four "themes which have been incorporated definitively into our life and mission thanks to the freedom Saint Dominic and his first Friars bequeathed to us."
"Juridical liberty, expressed in the law of the dispensation, was introduced in the beginning as a constitutional element;"
"moral liberty, for the Order wants that its laws do not bind under pain of sin so that the brothers may accept them with mature understanding, not as slaves under the law but rather as men living in freedom under grace;"
"liberty of initiative is expressed in the ius petendi et proponendi;" (roughly, the right to petition and to propose)
"historical liberty is expressed in the legislative or dynamic mobility itself of historical adaptation."
This freedom is absolutely fundamental to the Dominican Order. It predates the founding of the Order, since Bishop Foulques of Toulouse gave St. Dominic the freedom to do what he thought needed doing years before the Order of Preachers was formed. St. Dominic in turn intentionally and explicitly incorporated freedom into his new Order; he once said he'd take a knife and cut out of every copy of the Rule any words a Friar thought bound under pain of sin.
But it's a challenging freedom. A Dominican can't say, "I'd love to, but...
"...I've got to go pray now."
"...I'm morally bound to do something else."
"...no one's told me I could."
"...we've never done that before."
Not only does Dominican liberty take away a lot of respectable excuses, it comes with the risk of losing Dominican identity. The freedom bequeathed by St. Dominic exists in tension with the regular (i.e., ruled) life he insisted on for all the Friars. Less dramatically, Dominican freedom only makes sense within the context of overall Dominican life, and it's generally a matter of prudence rather than law to remain within that life while exercising that freedom.