Way to not even think at all, Deck Knight.
The point of Feint isn't the damage - it's strategic. Saying it's useless because it only does 50BP is like saying Knock Off is useless because it's only 20BP or whatever, when the latter is obviously an excellent move.
As far as Feint goes, the general idea is that, if a Pokemon is using Protect, it's trying to avoid Surf/Earthquake/Explosion/Discharge used by its partner, or possible something used by the Feinter's partner. When you use Feint, they've not only wasted a turn, they're a sitting duck for whatever is coming next.
Feint is usefull for strategy like Splash is useful for PP stalling.
Unlike Knock Off, Feint doesn't have the effect of crippling some opponents by disabling thier item.
Unlike Knock Off, Feint constitutes a free switch-in.
Unlike Knock Off, Feint is utterly useless if your opponents have moves other than Protect.
Knock Off has one of the best effects in the game to make up for its crappy Base Power. Hell, the Base Power is actually a bonus because it makes Knock-Off Taunt-Proof.
Feint, on the other hand, deals shit damage even when you properly predict Protect. The pokemon that learn it almost always have better options or already suffer from four-moveslot syndrome.
Let me illustrate:
The strongest user of Feint is CB Medicham. Lets assume you have a 2vs2 battle against Weezing and Metagross. You predict one of them is going to go BOOM, causing the other to Protect. So what do you do?
You could Psycho Cut Weezing, probably KO'ing it and hoping Metagross used Protect.
You could Fire Punch Metagross, KO'ing it and hoping Weezing uses Protect.
Of you could use Feint and get blown to bits either way every time, since your mighty CB Feint does 17% Max to Groos (min/min) and 26% Max(321 HP/max) to Weezing.
Feint has no strategic purpose until the Protecting pokemon is at or near 10% HP. Feint is useless in regular battles and too weak to be worth anything in 2vs2. Feint would be strategic if it had a 100% flinch chance like Fake Out, thus rendering a protecting pokemon helpless, but it can't do that either. The Protecting pokemon still avoids the hit from Explosion/Discharge/Earthquake/whatever, meaning the Feinter likely just got smashed for a lot more damage then they dealt to the Protector. GJ dealing 40% to Swampert, Groos just owned you and your partner with Explosion.
The point is, Feint does miniscule damage even to Protecting pokemon. It relies on the prediction of ONE SINGLE MOVE. It leaves its user wide open for attacks.
That is why Feint seriously needs a Base Power boost at least. There is nothing "Strategic" about using up a moveslot that only aids you when your opponent is at low HP, amd is using Protect to try and abuse Leftovers or Leech Seed recovery, and them barely beats out that Leftovers/Seed Recovery. Medicham is the most extreme example, and it doesn't even have room for Feint. The only thing I might see using it is Flygon, and Flygon is substantially less powerful.
I can think of no use for Feint when the pokemon using it would be more versatile and powerful if they were just SPAMMing powerful attacks.
Feint is, in short: high risk, low reward.
On that note, Users of Feint:
Raichu
Hitmonlee
Hitmonchan
Heracross
Hitmontop
Medicham
Flygon(from Trapinch)
Infernape
Lucario
Gallade
Pinsir
Yanmega
Gliscor
Blaziken
Toxicroak
Wow, Feint would have been a lot better if it were Fighting type, LOL. The only Steel type on this list is Lucario, whose defenses are very meh. Gliscor has the best defenses and is immune to EQ at least. Hitmontop has Intimidate.
Otherwise, none of these match Yoshi Kings Rock/Steel/Ghost type wishes on the first page.