We live in an age where balance changes are a regular part of fighting games. We all wait with baited breath whenever a patch is on the horizon, praying to every deity known to man that our character will get buffed, instead of nerfed into the ground. While nerfing certain overpowered tools is necessary at times, buffing weaker fighters is usually better for the life cycle of a game, instead of nerfing the stronger ones.
To examine this philosophy and give some reasoning as to why buffs are generally better than nerfs, Gerald from Core-A Gaming has gone into the history of both sports and fighting games, looking at instances where gives players more options to score or win a match has, more often than not, resulted in a more engaging game for everyone. From basketball, he takes the addition of the three point line and how this gave smaller players the chance to score, as they could avoid dealing with some lanky player guarding the hoop. For fighting games, he gives the example of the notorious Street Fighter II: Rainbow Edition and how while the game was beyond broken, it added certain elements like air specials, a teleport for Dhalsim and a fireball for Chun-Li that would go onto make Street Fighter more exciting, by increasing character options.
Psychologically, no-one likes to lose something of value and when a loss of a character option results in a game becoming less exciting, you can understand why people virulently hate nerfs. This does not mean nerfs are all bad, a clever nerf can actually give players more options, as seen with the changes to Shoryuken FADCs during the life cycle of Street Fighter 4.
As with every Core-A video, this analysis is worth a watch if you are interested in the methodology that goes into balancing a fighting game.
Source: Core-A Gaming