Players often hate to have their characters fail at anything. Handling failure can be a GM's biggest challenge to make the play fun and entertaining, no matter how the roll goes.
Heroes Never Fail
GMs can take the approach that the characters are playing heroes, so of course they never fail.
That doesn't mean the characters always achieve what they want to achieve, but it means that when they don't achieve it, they don't do so due to poor skill on their part.
For example, let's say that a sword wielding fighter is trying to attack a troll on a bridge. The player rolls a critical failure, and cringes. The GM could rule that the fighter trips and falls over the edge of the bridge, and is now hanging on by one hand, her sword falling to the rocks below.
But seriously...a hero tripping? Heroes don't trip, but they can be overcome by greater forces. A GM that takes the "heroes don't fail" approach would instead say, "The troll blocks your swing, rips your sword out of your hand and tosses it over the edge of the bridge. You he tosses the other direction, but you manage to grab one of the bridge ropes at the last second, narrowly preventing your death on the rocks below."
The end result is the same in both cases. One case, however, portrays the character as bumbling or unlucky, the other portrays them as a hero fighting against near insurmountable odds.
Make Failure Entertaining
If your players are okay with bad things happening to their characters, but get frustrated by a string of failed rolls, make the failures entertaining. Critical failure tables are an attempt to do this, by making highly unlikely results quite possible. A hero swinging a sword wouldn't be able to stab herself in the back, but if that's the result that comes up in the critical failure table, go with it.
Or toss the table, and pick the least appropriate result for humor value.
Just note that this might get old pretty quickly, and your players might tire of it.
Up The Odds With Each Failure
You could always go with the approach to make players hate failure even more, by increasing the odds against them for failures. A fighter swinging a punch in a tavern brawl fails to hit her target, but she's likely to hit someone. And that someone is now a new enemy to be managed, along with the original ones.
This plays well for humor value as well, and can be nicely mixed with unlikely critical failures for variety.
Give Something For Failure
Failed rolls might succeed, but with minimal effect. A sword slash hits, but glances off the opponent's armor, for example. The player at least feels that her character is competent and has executed the sword strike correctly, even though the end result is that same as a miss.
This is a milder version of the "heroes don't fail" approach, and can be mixed with it easily.
Whatever approach you use, remember that there's nothing more frustrating for a player than a steady string of failed rolls. Be prepared to do something to help them through it.