Well, that depends on what you want to do with the language you're learning. It may be fine to just learn some spoken language if you're just planning on traveling or visiting an area. However, if you plan on living there or becoming otherwise fluent in the language, the written form of it is a large part of that. If this is your situation, you should seriously considering learning the written form.

It can depend on the language. Thai is very difficult to express in romanised form and is often transliterated in a variety of ways each of which cannot capture the exact sound. "Bpai" is a good example: It means Go... as long as you are speaking in the mid-tone, change the tone and you change the meaning entirely. Also have you ever heard the Bp sound? It is somewhere between B and P but that means learning the very subtle (but sometimes very important) difference between the way the Thai speakers pronounce B, Bp and P. Similar problems can occur with the way other sounds are inducted into the format of romanisation from Mandarin and many other languages. In fact the further from Europe the language base, the more likely you are to encounter problems reading and writing well without the native alphabet. That's not to say it's essential or even important for a holiday or such. Nor is it generally a problem with languages closer to the European base.

in my case, at least at present,i don't think alphabet is that important. it is been one year since i begun to learn spanish, but at the beginning, i just spent two days to learn how to read the alphabets. till today, i don\'t even know how to read spanish letter. but, very funny, now i can read an anticle without any problem. jajajaja, in my opinion, no need to master the alphabets in a short time, in future learning, you will know them quietly. that is the way to learn a languange.