In addition, I realized that there are more usage of katakana words in modern japanese compare to japanese 50 years ago.
The country has also opened up to ALOT of foreign culture, and the best way to represent that is with katakana. I dont think you are going to see people using katakana as a replacement for hiragana/kanji anytime soon (other than for emphasis or effect).
I just wonder why can't they use some simple kanjis to replace the long katakana...
While katakana words may well be able to be written in kanji, you also have to remember the kanji THEMSELVES lend credence to the meaning of a word. "Hanasu" for example has a radical in it that is associated with speaking/language.
You know, I think reading pure kana sentences would be a lot easier if Japanese would start using spaces in between words.
Ha - this perfectly sums up the sentiment of so many Japanese learners (myself included). However it wouldnt neccesarily be easier for them since thats how they learned the language (well childrens book DO have the words spaced out). In time, one comes to "recognize" where words begin and end due to familiarization and seeing particles and expression enders/beginners.
The poster who made the comment about the NUMEROUS Japanese words that are spelled the same, really hit it on the head. Without kanji, contexualization would be all but impossible.