I'm not sure who "they" are
I'm very happy with the 210 VLD's in a 300 WM.
Many people warn against use of J-4 jackets up close, but as an extreme example, I shot a wounded Eland bull (shot by another hunter) at probably 10 or 15 yards right on the shoulder and the bullet reached the vitals and he was dead in 30 seconds. If you've ever seen the shoulders on an Eland you will know that this is quite something.
I've shot other fairly large animals as close as around 120 yards too.
No, I don't recommend them for Eland, but I'm saying they should be fine at 50 yards on most game animals as well as further out.
I love them.
That said, if you hunt in areas where bush in dense and you need to try to shoot at the southern end of an animal facing north to reach the vitals, I'd suggest something more strongly constructed. Not that I've tried it at all, so can't say that a VLD failed me.
The VLD design is great for a specific purpose as discussed elsewhere here and also on Berger's website, but I feel that I must be able to place a shot that requires no more than about 6 inches of penetration before being in the chest cavity. That's how I use them and awesome results so far.