The Ramchal makes numerous observations about human nature. One such observation is man’s natural tendency towards laziness.
The interesting twist to this human tendency, is that if one has the habit of constantly procrastinating, and delaying the fulfillment of necessary tasks, it is an indication, that he is greatly lacking, in the area of spirituality. He is very much connected to the עולם הגשמי, the material, physical world.
This is greatly in contrast to one who has overcome his laziness. He acts with swiftness and enthusiasm in fulfilling any task placed before him. He will not stay in bed more than is necessary, and will not make excuses for not getting things done on time.
The reason why the Ramchal sees this as a reflection of spirituality, or the lack of it, is connected to how one approaches the observance of Torah and Mitzvot.
The spiritual individual will not wait a moment if there is a good deed to be performed. If it involves synagogue attendance, he will be among the first to be present. He is passionate in his desire to do good in this world. He is spiritual.
Contrast this to our lazy guy. He is late to Shule if he attends at all. He gives numerous excuses, when asked to participate in a Mitzva. He is not very spiritual at all. He is connected too much to the physical world.
This is a very clever observation about human nature. Aside from the more lofty goal of achieving spirituality, it should clearly be recognized that laziness is a negative character trait, that must be overcome.