If there is a thread about bootstrap, some one posts "why must everything be bootstrap?" Get a thread about a bootstrap alternative and...... bingo!!!!
(Not having a go at you personally, Im sure your question was genuine. Just making general observation of the irony)
I think a good enough reason is because some one could. No reason why some one cant just say; I can do that too, and I know lots of people say they would like an alternative, so lets just give it a go and see if any one likes it enough to use. And for me, that's good enough.
Giving it a go for no obvious reason is the blood of a "hacker", IMHO. Its the doing of it that is of value. One learns form the experience.
What's the difference from Bootstrap? Why don't you view its source? Read through the framework's documentation? For one the default styling is significantly different than Bootstrap.
The one thing I fondly miss about Slashdot is people would liberally tell you to RTFM when you asked something obvious that could have been answered by reading the article posted.
I disagree with your original comment. Yes, we can read the source. Yes, we can analyze it ourselves. But time is limited to all of us. The product should state exactly how it is different with the competition and why we should pick it. This is similar to how pg asks startups to describe themselves in one simple sentence. You don't tell pg that he lacks critical thinking for not reading my website.
Stating how you are different gives the customers focus. If you state that you are different because of X then you can go into the code and look at X particularly.
Options are fantastic. Who loses? It's a win-win.