This is what nutritionists have been saying for decades -- too much protein, especially animal protein, isn't good for you long-term. But you can get short-term weight loss from it and also it does help if you're trying to add muscle, and most people seem to prioritize these things over health. The truth is, the paleo diet isn't one diet, it's several, and all of them are marketed to make money, not for health. The whole premise is that in our pre-history we ate a whole bunch of animal protein and didn't eat grains and the like, and this isn't factually true -- animals were very hard to catch and plants were very easy to catch, so people have always eaten mostly plants until some migrated to places unhospitable to plants, such as the far north or very high altitudes, or in the great plains where mostly grasses grew. Those people did eat mostly animal, but what records we have show short life spans.
No, Paleo diet is very good for health included heart health and other health, because paleo diet is rich in fruits, vegetables and nuts, which are all elements of a healthy diet. These foods are not only healthy but also very cheap.
I personally do not believe in a one-size-fits-all diet. Diet depends upon many factors like the health of the person, region where he/she stays, what physical activities he/she does throughout the day and many more. And yes I would say the paleo diet is not all a good option for Vegetarians.
Paleo diet has both negative as well as positive effect on heart health & its's always better to take advice from doctor before starting a diet.