Almost all those people charge for the PDFs. They know the PDF is more useful, that's why the video is free.

I don't think your software is (or should be) illegal. But it's a form of theft, and incredibly unethical. These people worked very hard on these tabs and don't make much money. You (and kiaansaraiya and neogenix) should be ashamed of yourselves. You don't deserve your guitar if you steal tabs from working musicians.