Because if you werent willing to trade it and put it in danger early in combat, then your opponents knew that that creature was actually precious and then that would be the one worth killling if they ever got the opportunity, which would be rarer, because again, people were running fewer removal spells, because they were too expensive
Brawl Legal Vintage Legal Timeless Legal Commander Legal Pauper Not Legal Oathbreaker Legal Penny Legal Toolbox Buy This Card Notes and Rules Information for Leyline of Lightning: If you cast a creature with bloodthirst while Leyline of Lightning is on the battlefield, you may use the Leyline's ability to deal damage to an opponent
If you happen to whiff with this ability, you get some treasure tokens in return, so its not all bad even if you hit no legendary cards
- Sacrifice them for value
With Tevesh now at the helm, we can utilize our creatures beyond just the abilities in the card text