I'm guessing that's not the example you're looking for, as Half Moon Bay is further from LA than Sacramento is from LA.
That's just the irony of some trip planning you currently have to do in order to current HPC network in Japan. Using the US example again, if there were 3 charging stations on highway 1 between Half Moon Bay and Los Angeles, but none within your car's range on I-5, you might actually have to take the coastal route to make the trip. It's a much nicer route of course but in most cases it would better to avoid it if you could. What TEG said about Roadster drivers is correct however -- they don't mind the 20 mile detour. I certainly don't mind it if I have time as I love driving. But I think you are missing the main part of the point I was trying to make which I'll explain further here.
In Japan, all major highways are toll roads, and they are extremely expensive compared to anything you've maybe seen in the US. $50-60 perhaps to drive 300 miles. The further you go, however, the better your cost performance. Just getting on the damn thing for a 5 mile trip costs you perhaps $12.
The highway network is extensive linking pretty much all major cities, and compared to non-toll roads, travel on the highways is many, many times faster. I would say that on the highways you can easily average 120km/hr (go faster than that and automated speed traps snap your picture and you get a ticket in the mail) for long trips, but on non-toll roads you can maybe average 20km/hr combined with the fact they are generally not built in a straight path because of the mountainous terain that encompasses most of the country. Lots of twisty mountain roads here! And lots and lots of traffic lights that are not timed well. In Japan on non-toll roads you spend more time waiting at traffic lights than you do driving. This is not an exageration. The highways on the other hand are straight as an arrow, flat and level, and burrow straight through mountains with tunnels as long as 20 miles if a mountain happens to get in the way. Simply put, you want to be travelling on these roads in most cases if your really need to get anywhere.
The problem with charging an electric car anywhere other than the service areas along these roads is that you need to get off the highway, drive to the charging station, and then re-enter the highway though another toll gate. The toll gates are also very spread out, so you may need to drive even further to get back on then when you got off. And when you do get back on, they hit you with a brand new toll which probably is going to drive your total fee up by 40 or 50% since you have now down 2 trips on the toll road rather than 1 if you had been able to charge at a highway service area which if right on the highway. You never have to exit, you don't have to pay a 2nd toll, and you don't have to wait in line to get back on the highway.
Now, I'll write a bit about the highway service areas that feature CHAdeMO charge points. These place are great -- they feature all sorts of restaurants, shopping, parks, and are generally a great place to stop at during your drive. They are the perfect place to charge, in fact there couldn't be a better place to stop really. Wouldn't it be nice if they let Tesla put some superchargers or HPCs there too? It's highly unlikely, probably impossible that it will ever happen. Japan is very standards based society, and if the CHAdeMO is the standard, that's what's going up (well, already is up I should say) at highway service areas all over the country. They simply won't put in a charge point that is not capable of charging Japanese-made cars, case closed.
So if Tesla does not support CHAdeMO in any form, they are going to sell a lot less cars in this market. I shouldn't say they are going to fail, obviously nobody knows that. So I retract that statement, they may still achieve some level of success with a certain segment of the market. The long range achievable by Tesla cars does as you say mitigate a lot of the consequences of not having a convenient charging network in place. But I will guarantee you 100% that they will sell way, way less cars here that if they had decided to support CHAdeMO.
Let me know if this makes better sense now, I hope I've done a better job of explaining it!