Dear Mr.aviduser,

The Word "Inshallah" means (By Allah's Well) which means everything couldn't be happened unless God wanted it to happen..this is a true and well known fact in Islam.
And if some people use it wrongly to express the fact that they don't know or (don't bother me) are people who don't want to work or doesn't do thier work properly, so they are misusing the above mentioned fact in a way they can escape from their duties and responsibilities.
Hope I make it clear for you so we don't blame a great Islamic word like (InshaAllah), but balme the one who is misusing it.

Thanks