No, that's just vegetarian propaganda at work. We have this stuff in our stomachs called HCI (hydrochloric acid) which begins breaking down food after we chew and swallow it. It can dissolve metals, and our entire digestive system, from saliva to colon, is geared to digest meat as well as plants, not one or the other exclusively.
If meat were "hard to digest", you'd be pooping out chunks of meat and have massive stomach cramping and all sorts of issues. Alas, meat is completely digestable, and what your poop is really comprised of is insoluble fiber (from plants, no less!), dead bacteria, mucus, and any remaining undigested food (short transit time).
It all depends on the condition of your health. If you're deficient in hcl acid and pancreatic enzymes and have dysbiosis/leaky gut, it'll be harder for you to digest. If you have a properly functioning digestive system it's not hard to digest, it just has a longer transit time than carbs do through the gut, which isn't a bad thing if you're trying to eat less since it keeps you fuller longer. As someone else mentioned, our gut is designed by evolution to eat both meat and plants, the problem is many people nowadays do things to their body that it wasn't designed to handle, causing an inability to function the way it's supposed to. The red meat/saturated fat myth has been thoroughly debunked, check out other posts about that. Of course if you listen to anyone in the media or conventional medicine they'll tell you the opposite, but they just believed what they were taught without doing any research on their own.
I've seen plenty of undigested food come out in my stool; corn, spinach, thai noodles (sorry for TMI). I've never seen undigested meat in there. The whole "meat rots in your colon" thing is straight up vegan propaganda and shows what we're up against in the effort to get the paleo viewpoint out in the world.
Speaking for myself, red meat actually settles my stomach. It is easy for me to digest, in fact it helps me to digest other things too. This is not as true if it is cooked well done, only if it is rare. I understand that not everyone has the same experience, but clearly something about my system is well adapted to red meat.
Honestly, the answer depends on your genetics and the gut flora you've cultured. Some people absolutely thrive on meat but I've heard from some people coming off vegetarian regimes that they had to start small and affect a slow transition.
Red meat is the only major nutrient that has NEVER caused me problems--no bloating, etc. I had gallbladder surgery about 7 years ago but even fatty beef gives me no issues. I don't believe my gallstone came from meat, either, but from what I now know is a strong intolerance for wheat. In fact, the only meat that has been a bit much was goose. If I eat a large meal of goose I take bile salts to avoid overload.
Others start with seafood and tiny amounts of meat daily, gradually increasing as their comfort grows.
I actually eat a lot of raw meat now, I find it very easy to digest, it does not feel heavy in my gut like cooked meat can at times, elimination is good too. I had my gallbladder removes over 20 years ago and do not have any issues digesting fats or meat at all. I am LC-VLC and that evolved naturally for my body.
IIRC, animal products are they only (or almost only) foods that the our body actually digests on its own, via enzymes. Everything else sits in your gut while it is digested by bacteria. That doesn't mean that non-animal products are bad, but the idea that meat is hard to digest is completely false. Meat is easily digested by the human body.