Here is my reasoning.
- It does nothing you can't do for free in the IDE you undoubtedly already have.
- The result looks far worse than a mock up you can create in your IDE.
- Once you have the mock up you can't do anything useful with it except export it as an image or print it. You can't, for example, actually use that for a real form later in the project's life cycle.
- The result looks crap. Not poor, crap! It looks like a 7 year old has drawn it with a wax crayon....a blunt one.
- Balsamiq brought in revenue of over 100,000 US Dollars in its first 5 months.
I rest my case.