Sorry, but this just sounds like good old fashioned bias. The difference between reality and what people "like to think" can be quite significant. The food you've been eating in CA may be delicious to you, but perhaps it simply does not reflect the reality of typical Thai food. Given that the central coast is not exactly a hub of southeast Asian expat culture, I strongly suspect that may be the case.

I've divided my time between homes in California (native) and Bangkok for many years. My Thai friends in the USA are mostly unanimous in saying that they do get reasonably good Thai food from a select few restaurants in the LA/OC area (home of the largest Thai expat population in the world), but that even those best eateries just aren't as good as the stuff in Thailand.

In my experience, they are 100% correct.

In what part of the city? Which restaurants? What kind of Thai food? You do realize that there are pretty significant regional variations, right? For example, Thai food is not necessarily spicy on the whole—Isaan and southern dishes tend to range from pleasantly spicy to inedibly hot, while central Thai tends to be mild, and comparatively bland. Do you have any idea which of these regional influences you've been eating in Cali?

Again, your expectations seem off. Spiciness is widely variable, from cook to cook, dish to dish, region to region. And why on earth would you assume you'd find every dish full of basil?

There's also the matter of individual taste. Several posters have advised you about the condiments that are ubiquitous at most Thai tables, especially from street vendors. The chef makes his or her recipe the way it's "supposed" to be, and invites each person to adjust it to his or her own preference. I can't tell you how many of my Thai friends really dislike spicy-hot food, and have virtually no tolerance for it. It's a source of endless teasing between us (my tolerance is very high).

In general, even when ordered by Thais, I've found that relatively few dishes come out very spicy unless you specifically request it (bpet-bpet). And even then, you'll probably have to insist that you really do want it "Thai" spicy (not farang spicy). And even then, they often still won't believe you and will "protect" you by sending out relatively mild (especially in Bangkok, and especially where there are lots of farang eating).

Besides, the art of great Thai food is balance, hitting all five favors in one dish or meal in exactly the right combo. The fact is that extremely spicy-hot food kills the palate, and all the subtlety of those intricate, carefully achieved flavor profiles is completely lost.

You may need to educate yourself further about what constitutes truly good Thai food. Learn about the regional ingredients and variations. Drive down to SoCal and try Thai food in LA's Thai Town neighborhood, or around central OC.

And, the next time you come to BKK, instead of taking a food tour, try taking some of the excellent Thai cooking classes that are offered all over the city. Then, consider visiting other regions—if you like spicy, you'll be fine in Chiang Mai and the southern provinces, and the cultural experience will be vastly different from Bangkok.