"I hate myself for being lazy" has 36.000 results on google, which suggests some people at least don't think it's alright (i.e. don't use the same definition as you).

But even if the term "Akrasia" was clearer than "lazy" (I agree it may be), you could say:

• "Akrasia" is clearer than "Laziness" because it has a more precise meaning
• "Laziness" is clearer than "Akrasia" because much more people know what the word means

I don't really think our use of the word is a problem tho, it's just worth keeping in mind that we're trading off a little bit more precision for being less understandable to the outside world. But that's always going on with jargon.