Bad in what way exactly? Hiragana and Katakana are easier to pick up, because there is more burden placed in learning each individual word. With the baseline investment to learn the Kanji in place, each new word is just a composition of characters and their associated ideas that you already know.
You can do the same thing with dictionaries in Japanese or Chinese, though it works best if you use a dictionary that lets you handwrite in the characters (it helps a lot if you learn your radicals and stroke orders well, so that you can easily write characters you don't know).
Oh, so, my point was that using Japanese was a bad example, precisely because two of the three alphabets are used nonlogographically. It is also my understanding that new words and loanwords are spelled out phonetically in those alphabets, instead of grafting some new character into the kanji.
"if you use a dictionary that lets you handwrite in the character"
I'm unfamiliar with any paper dictionary with that capability.
You can do the same thing with dictionaries in Japanese or Chinese, though it works best if you use a dictionary that lets you handwrite in the characters (it helps a lot if you learn your radicals and stroke orders well, so that you can easily write characters you don't know).