The Noda B'Yehuda the legendary Rav of Prague in the 1700's asks why does the gemara say "Gadol Yegia Kapoi Yoser MiYirah Shamayim"; greater is one who toils to earn a living than one who has Yirah Shamayim. Of course if you earn you own keep AND have yirah shamayim you are on a higher level. If you have no yirah shamayim you are certainly on a lower level.
He explains that what it means is greater is the one who earns a living with the work of his hand than someone who is offered a position as a Rav because they think he is a yirah shamayim. This can be the explanation of the Mishna (1:10) better to work than to be awarded a salaried Rabbinic position.
The Kotzker Rebbe offers a different explanation. He says our mishna is referring to the different aspects of a Rav's job. "Ehoiv Es HaMelacha"; The Rav should love the work he performs in his duties as a Rav and do it with dedication, "U'Snah Es HaRabbanus"; He should hate the pomp, glory, and honor that is associated with the job.