Glenn is the king of self-deprecation. At solo shows, the vast majority of his jokes are at his own expense. Now, these are all in good fun, of course. However, it goes to illustrate that despite those who would accuse him of an oversized ego, he acts very humble. He is always generous with his praise of his bandmates and reluctant to "toot his own horn." Indeed, he's often downplaying his own contributions in favor of others (as the above quote shows).

Still, I don't think that he considers his own songs unimportant or his work to be inferior to Don's, although his comment does seem to imply that. I just think he was trying to compliment Don and went too far.

I also want to add that while Don doesn't directly compliment Glenn in the article, the way he talks about Glenn's role as leader shows that Don respects Glenn and it is an indirect compliment. Additionally, we don't know what was edited out by Young. It's possible that Don did praise Glenn directly and Young simply left it out in favor of the drama.