What are you missing?  Nothing from what I can see.  If anything, you are hitting on precisely what I was trying to get my mind around when dealing with the complexities of operating certain businesses in this modern era.  My initial question was on the ethics, in view of tradition, of operating a restaurant that served primarily meat.  For those that piped in about providing non-meat alternatives on certain days miss the overall point of the post. From a traditional viewpoint, the restaurant owner should strive not to serve meat on any Friday, and Ash Wednesday.  However, unless said restaurant was located in some enclave of practicing traditional Catholics, I do not see this being a viable business option.  (And again, for those who think the solution is as easy as simply providing non-meat alternatives on those days simply do not understand BBQ--another reason why I selected that type of restaurant in the hypothetical).  

Under the present rules, though, and regardless if one believes them to be in effect or not, meat is only forbidden on Friday's during Lent and Ash Wednesday.  Under that paradigm, I could see the potential of simply not opening the restaurant on those days and still remain economically viable.  And in view of the fasting requirements of Ash Wednesday and Good Friday, the restaurant would certainly have to be closed on those days.    

From a larger perspective, and revisiting your theme of things as they should be, it is sad that as a "Christian" nation, the U.S. has, generally speaking, shifted so far from its apparent roots.  More and more, Sunday "blue laws" are stricken, and Sunday becoming like any other business day is the norm.  While I'm sure there are more, Chick-fil-A is one of the only national-chain restaurants that at least chooses to not open on that day.  Moreover, as Catholics, I am unaware of any type of the enclave I was mentioning above.  And while there very well may exist such an enclave, they are few and far between.  Compare/contrast that to the many enclaves that presently exist in just above every major U.S. city today, especially, for example, Jєωιѕн and Islamic people who purposefully take over neighborhoods and instill their own "local rules".  Most of this is done out of their own volition, and yet just look at all the interesting responses here about whether a restaurant should be serving meat on Fridays.

I do not believe the above to be entirely true.  I believe it would be more accurate to say that an un-baptized, non-Catholic unaware of the Church who eats meat on Good Friday does not sin.  All baptized apostates and heretics are still subject to the one, true Church, and by eating meat on Friday, are arguably engaging in sinful behavior, in addition to the very sinful behavior appurtenant to being an apostate/heretic.  In other words, for example, Lutherans aren't off the hook for eating meat on Good Friday simply because they refuse recognition of Christ's one, true Church.

In view of the following, unless you're living in, for example, an Islamic country or the like, I think it is a canard to say that one simply does not know the "religion" of the customers, and as such, the BBQ restaurant owner can not be at fault for serving meat on a Friday during Lent.  Add to that, if said restaurant was located in a small town where the owner knows most of the patrons (and just about any small town in American is essentially "Christian" in nature), it would be a near impossibility that the restaurant owner was unaware of his/her patrons' religious affiliation.  In short, by simply providing meat products on any Friday during Lent (and especially Good Friday), even if the restaurant owner didn't eat them, s/he is still contributing to the sinful behavior of others.

And the likely outcome...

Upon taking the advice of others who have never run a restaurant, Catholic entrepreneur invests life savings into BBQ restaurant in a historically Catholic area that adopts the above model.  Food is fantastic.  However....

--N.O. Catholics show up on Fridays outside of Lent, and are shocked that there isn't any meat on the menu; is accused of being antiquated and prejudiced against the local Protestants ("the Church doesn't teach that anymore..."); local priest and bishop agree; is labelled a "traditionalist" and "rigid"; Susan from the Parish Council organizes a boycott, which is successful.  

--Catholics from the nearby "traditional community" refuse to patronize the establishment; Comments such as "It's overpriced and we can't afford it," and "We can make the same food at home for less" are overheard; Of the two women employed at the restaurant, one has short hair and the other doesn't wear a skirt that covers her ankles--each considered to be scandalous and thus the restaurant must be avoided; restaurant owner is accused of not being a true Trad^TM.

--Restaurant owner eventually files for Chapter 11 bankruptcy; loses everything.  

--Restaurant building is bought and repurposed as a halal restaurant serving the local Somali population brought into the area by the USCCB and paid for by Federal tax dollars; business thrives.

A good Catholic would just embrace your outcome with a "Blessed be God"...

Canon law only applies to Catholics. A non-Catholic who eats meat on Good Friday does not sin, and therefore a Catholic who serves him meat is not participating in sin.

Not eating meat on Fridays was issued for Catholics.