There's plenty of other bonuses to damage which do make the difference more negligible, but it's worth actually looking at the numbers instead of making false assumptions.
Look, I know that if you evaluate the numbers, it is more damage (significantly, see some of my earlier posts). My point is, at the table, against monsters (say hobgoblins) what is the difference between:
Dex-Monk: Roll-to-hit, Hit!, 8 damage!
Str-Monk: Roll-to-hit, Hit!, 12 damage!
My point is they are both good hits, but I don't think the extra
4 points of damage are going to be so awe-inspiring that the harrier monk suddenly becomes a 'true threat'. Either the dm adjucates the monk is a threat or he doesn't, but in my experience DMs follow what has been occuring in combat, not what is written on your character sheet. A rogue with an early lucky crit and sneak attack damage will likely be deemed the biggest threat, until a fighter or barbarian moves in and gets a full-attack. Wizards and other robe-wearers always have a threatening aura to them, for their spell-casting hands of destruction.The monk, even a strength monk, is going to be hard-pressed to seem more threatening than those characters (so honestly, don't try too hard!).
My point is, don't kid yourself and play your role. Help the rogue flank, chase down a spell-caster, or disarm/grapple/trip/stun someone. Don't try and stand your ground and make full attacks (ala Fighter or Barbarian) because you don't have the hp or the attack bonus to make it worthwhile (except against mooks, which you can pretty much do ANYTHING and have the fight go well).
All of that is not to say that a Strength-monk is not viable, I simply don't think that becoming a strength monk to the detriment of the rest of your character is a worthy build (especially for a first-time monk). And trying to say that is the
only viable build (unless you are extremeley tactical, have good teamwork, etc) irks me.
it's still a difference of 50% - like watching a car drive past at 60 mph vs 40.
I'm pretty sure unless I was really paying attention I would never notice the difference of 20 mph. Kinda like, in the heat of battle you wouldn't notice that a monk's wounds aren't *quite* as bludgeoning as they would be with a stronger monk (although I do respect the 'low strength equates to a visually weak-looking character' argument, however anyone willing to go into battle without a shirt that manages to not get sliced up in the first round would raise my eyebrows). This isn't final fantasy with numbers popping up in front of your chest when you take damage, after all.