If something's commendable it deserves whatever praise it receives. When you developed a car that could run on solar power, that was a commendable accomplishment. Now, it's time to move from Seattle.
Coming from the verb "to commend," commendable can find its roots in the Latin commendāre, meaning "to praise." So, it only makes sense that someone who has done some commendable deed should get praise for it. American author James Branch Cabell once wrote: "While it is well enough to leave footprints on the sands of time, it is even more important to make sure they point in a commendable direction."