The emphasis in Tennyson's poem, "Ulysses," is not on the failings of the people of Ithaca, although they are mentioned.  Most of what is revealed about them is contained in lines four and five:  they are "savage" and "hoard, and sleep, and feed, and know not me." 

The people of Ithaca, then, in the speaker's view, are violent, uneducated, obsessively hoard food, etc., do nothing but eat and sleep, and don't understand Ulysses.  Presumably, they don't know what they have in the hero of The Odyssey.  Presumably, they don't honor and listen to him as they should.

The people are also "rugged," as mentioned in line 37.  It will take a calm, mild-mannered, diplomatic man like Telemachus to "Subdue them to the useful and the good."  Ulysses is an adventurer and a warrior, not a diplomatic leader, according to the poem.

Tennyson presents Ulysses as somewhat of an artist.  His adventures are artistic.  His mindset is not that of a diplomat.  He longs to be off on an adventure, and he wants to leave the leadership of his people to someone else. 

In Tennyson's "Ulysses," what does Ulysses think of his people?

In Tennyson's "Ulysses," the eponymous king is fairly unabashed when it comes to his opinion of his subjects, the people of Ithaca. Take, for instance, Ulysses' first description of his people: 

...I mete and dole
Unequal laws unto a savage race,
That hoard, and sleep, and feed, and know not me. (3-5)

From this quote, it's clear that Ulysses regards the people of Ithaca as an uncouth, uncultured rabble. Indeed, according to the king's account, it would appear that the subjects of the kingdom are more similar to dumb beasts than human beings. Ulysses underscores this opinion later in the poem when he refers to his subjects once again, calling them "a rugged people" (37). All in all, it's quite clear that Ulysses views the people of Ithaca as uncultured bumpkins unworthy of a legendary king such as himself.

However, there are other layers present in Ulysses' dislike of his subjects. It would appear, for instance, that much of the king's resentment stems from his belief that his people "know not me." In other words, Ulysses dislikes his people because they make no effort to know and respect him as a unique individual. Instead, they simply view him as a means to security and provision. As such, Ulysses links his lack of individual fulfillment to his responsibility to care for his subjects, and so he resents the "rabble" that have forced him to give up a life of glorious adventure.

Considering these two layers, Ulysses begins to seem remarkably insecure. While it's true that his subjects don't see him as an individual, it's likely that Ulysses similarly does not know any of them as individuals either, and in this light his despair seems suddenly moody and unreasonable. All in all, it's possible to see Ulysses' dislike of his people as a misplaced grudge, one which actually stems from his dislike of his kingly responsibility but which has been unfairly placed upon the shoulders of Ithaca's citizens.