Not knowing what you've been exposed too, it's hard to qualify that statement.
For instance there have been 5 folks here over the past 5 years that said the HFM HE-500 had crappier bass then the HE-400. 4 of them turned out to have them badly under powered, and when they switched, they realized they were wrong.
Having heard a lot, but far from all, my conclusions:
Closed backs with pumped up bass: all suck - any technology
Open backs can be great, good, or not so hot - depending on the quality of the driver.
I'm into stage, timbre, speed, transparancy, micro detail - hate bright/sibilant treble, or fat, sloppy bass. Every technology has entrants into that small group. I have heard more planars that aspire to that group, so there are more members from that tech on my list. The cheapest can that can do it - but not imaging, or low bass impact is the HD-600 - but only on an OTL amp. The best: DCA Voce (with the new pads, even better) for an estat has bass, and has the most natural treble timbre. Still not heard the new Rall which is getting rapturous reviews from people who have actually heard it. D8000, OG LCD-4, HFM HEK v2, Susvara, HD-800 (over the S, but with mod) are some others.