MPC's are known to give a grimy, low-bit, crunchy, rustic effect to drum samples. This was relevant with the MPC 60 or even the SP 1200 back in the day. If you listen to, Jay-Z's Dead President's for example, that entire track was done on an SP 1200. All of the drums were sampled and the producer couldn't play bass, so they filtered the bass from the sample and EQ'ed out all the Hi's so it just had a Lowpass on it, and they layered that to give it bass. The MPC 60 sort of just connected with R&B/Rap Producers alike, maybe because a lot of them didn't have real instruments, allowing them to take whatever sample they wanted and use it, chop it up, whatever, to get the most out of what they had. Anyways, I'm going off topic a bit, but the bottom line is that these samplers gave drums a raw, crunchy, sound. This became the standard for old school hip hop. The MPC is also a solid piece of hardware, with great features, you can rig your entire studio to an MPC.
However, that statement is complete fallacy. I've never heard such bullshit. It doesn't matter what hardware or software you use to make beats, it's how you use it. And you definitely don't need an MPC!
I can do most of what an MPC does Sample wise on Kontakt 3, and more.
It's easy to dirty your drums up, add a lo-fi effect, or whatever. Personally, the industry standard is the complete opposite now a days. For a true sampled hip hop beat, sure, dirty drums are essential, but, for everything else, including R&B/Commercial Rap, CLEAN CRISPY drums are the ticket.