Running 3 Solemn Judgments in a main deck can easily Backfire. Most burn decks aren't reliant on 1 key card and giving up half your life can easily do you in. Standard beatdown is rarely hurt by Solemn Judgment as they just aren't hampered that much by it.
Solemn Judgment works great against the more One-Trick Pony style decks that revolve around some OTK combo. Solemn Judgment is also great to protect your key monster such as a Silent Magician LV8. The point being in a side deck you can always swap them in if you are up against somebody that relies on something too heavily. But as a main deck option (unless you run something truly worthy of that type of protection) there are less costly ways to protect your standard garden variety level 4 monsters.
Solemn Judgment works great against the more One-Trick Pony style decks that revolve around some OTK combo. Solemn Judgment is also great to protect your key monster such as a Silent Magician LV8. The point being in a side deck you can always swap them in if you are up against somebody that relies on something too heavily. But as a main deck option (unless you run something truly worthy of that type of protection) there are less costly ways to protect your standard garden variety level 4 monsters.