False teachers blasphemed the good, glorious celestial beings?

NIV, 2P 2:

1 But there were also false prophets among the people, just as there will be false teachers among you.

Peter addressed false prophets and teachers (F1). F1 disrespected authority.

6 If he condemned the cities of Sodom and Gomorrah by burning them to ashes, and made them an example of what is going to happen to the ungodly … 9 then the Lord knows how to rescue the godly from trials and to hold the unrighteous for punishment on the day of judgment.

Peter likened F1 to the ungodly people of Sodom.

10 This is especially true of those who follow the corrupt desire of the flesh and despise authority. Bold and arrogant, they are not afraid to heap abuse on celestial beings.

Strong's Greek: 1391. δόξα (doxa) — 167 Occurrences

BDAG:
① the condition of being bright or shining, brightness, splendor, radiance
ⓑ of humans involved in transcendent circumstances, and also transcendent beings: cherubim
② a state of being magnificent, greatness, splendor, anything that catches the eye
③ honor as enhancement or recognition of status or performance, fame, recognition, renown, honor, prestige
④ a transcendent being deserving of honor, majestic being

ESV translated the word more literally:

and especially those who indulge in the lust of defiling passion and despise authority. Bold and willful, they do not tremble as they blaspheme the glorious ones,

Were the glorious ones (D1) humans?

Probably not; D1 were heavenly beings as translated by NIV:

11 whereas angels [A1], though greater in might and power, do not pronounce a blasphemous judgment against them [D1] before the Lord.

Other heavenly beings(A1), mightier than F1, didn't blaspheme D1.

Were D1 good angels or bad angels?

It was ambiguous.

12 But these people blaspheme in matters they do not understand. They are like unreasoning animals, creatures of instinct, born only to be caught and destroyed, and like animals they too will perish.

F1 were being arrogant. They didn't respect good or bad authority, heavenly or earthly. They would perish.

Elsewhere, Jude 1:

4 For certain people have crept in unnoticed who long ago were designated for this condemnation, ungodly people, who pervert the grace of our God into sensuality and deny our only Master and Lord, Jesus Christ.

These ungodly people (U1) were false teachers:

7 just as Sodom and Gomorrah and the surrounding cities, which likewise indulged in sexual immorality and pursued unnatural desire, serve as an example by undergoing a punishment of eternal fire.

Peter also mentioned that false teachers were like people of Sodom and would perish.

8 Yet in like manner these people also, relying on their dreams, defile the flesh, reject authority, and blaspheme the glorious ones.

U1 also rejected authority and blasphemed the glorious ones.

9 But when the archangel Michael, contending with the devil, was disputing about the body of Moses, he did not presume to pronounce a blasphemous judgment, but said, “The Lord rebuke you.”

This paralleled A1 didn't blaspheme D1 in 2P 2:11.
A1 || Michael.
D1 || the devil.

10 But these people blaspheme all that they do not understand, and they are destroyed by all that they, like unreasoning animals, understand instinctively.

Note the "unreasoning animals in 2P 2:12.

The parallels between Peter and Jude are significant. They were talking about the same group of people; U1 was F1. They rejected authority, arrogantly blasphemed supernatural powers, and behaved like irrational animals. They would face destruction/judgment.

Did the false teachers blaspheme the good, glorious celestial beings?

No, they blasphemed the devil's angels. Still, it was wrong because they arrogantly presumed to pronounce judgment on beings whose judgment belongs to God. Do not presumptuously take upon yourself God's prerogative of eternal judgment.