That's an understandalbe perspective Dark Espeon.
The reason why I think Beast Ring is still good for this deck is because it's a discard deck, meaning you can do huge damage if you discard on attack. The Energy Recycler in my deck makes sure that I have the ability to search out the energy I need upon playing Beast Ring, including the metal.
Energy Loto is a good card for digging, but just because you dig 7 cards deep to look for energy doesn't mean that you're going to find specifically your Unit Energy or Beast Energy. You might just hit Psychic energy the whole time. On the other hand, if you struggled to find metal energy in the early game and that's exactly the reason why your opponent got an early KO, then Beast Ring becomes a guranteed way to immediately go on the counter attack. 2 Beast Rings will allow you to immediately put 1 Metal and 3 Psychic onto one UNGX, and the triple discard will net you 260 damage, enough to OHKO anything currently printed, and then you have the metal energy on at least one UNGX for the time being. If you are concerned about the long term, you can split your Beast Rings to put 1 Metal and 1 Psychic on two different UNGX, and then you have options even if one gets KO'd.
The thing I always want to re-emphasize about Beast Ring is that even though you have a specific 3-4 prize window, you can very realistically play all 3 of them in one turn thanks to Steven's Decision (you have to use him 1 turn in advance if you're expecting to get KO'd), and the amount of momentum that you can gain from charging up two UNGXs with 3 Beast Rings is too valuable in my eyes to take it safe & slow with Energy Loto. I don't think you have to guarantee turn 2 attacking if you can set up so much momentum to control the rest of the game after someone takes one KO on you.
Also, unless you had a perfect opening game where you opened UNGX on bench, attached a psychic energy, discarded another psychic energy, set up an Inkay, then on turn you set up Malamar, Loto'd for Metal, and then used Malamar to put the discarded energy on UNGX, the max power UNGX you'll have at this point is swinging for 180, which is just fine for the mirror or vs Buzzwole GX...if you have Choice Band as well. Otherwise you won't really be taking a very valuable KO with 100/180 damage on turn 2 anyway.
Not to mention if you really need Metal/Unit Energy, why not just make that one of the cards you search out with your turn 1 Steven if that happens to be the play you go for?
I dunno. Personally I think Beast Ring has far too much potential and revenge momentum for it to be ignored, and the fact that it guarantee searches energy out of your deck means that you never have to worry about missing with Loto.