What was the immediate, practical reason Messier began compiling the list of fuzzy, non-moving patches?

Answer

To prevent repeatedly wasting time investigating the same fixed objects

He started compiling the working list to record these persistent blurs so that he would not waste time re-investigating them and mistaking them for a new comet discovery.

What was the immediate, practical reason Messier began compiling the list of fuzzy, non-moving patches?
astronomydeep-sky objectscelestial objectsCatalogcatalogueMessierCharles Messier