A friend told me JBL DD67000 is actually very bad speaker, is it true?

He is telling you that because he reads the audio rags and wants to sound smart.  JBL is an old, mainstay name and can't possibly make a speaker that would compete against the current darlings in the audiophile world.

While attending AXPONA this past April, I am ashamed to admit that I walked into the JBL suite with these same preconceived notions about JBL. I walked out over an hour later smiling because I just heard the best speakers at the show - the Everest DD67000's.  The presence they projected made music simply sound real.  And with all types of music too.  I did not hear this truth and presence in sound with the above darlings that were also at the show. 

I now know what's possible with high end audio speakers and they were JBL's.  Bravo Harman International! 

Depends on the JBL! :)

I'm no fan of their current powered mini-monitors at all, but I haven't heard the high efficiency or high output types in a long time.  Worth checking out.

Also, a lot of boutique speakers get extra "imaging" but putting a dip in the response at 2.4 kHz or thereabouts. It's a trade off of timbral neutrality for it. 

For price though, I'd probably forego the consumer horns and see how much the pro studio monitors were running instead such as the M2.

No.  It is not true.

not true

Tidal, Kharma, YG, Magico, Vivid G1, Grande Focal and German Physik
speakers are all mediocre IMO.
So is JBL.