Aw congrats to her, that's amazing Shame she can't be there
She could be there if she wanted to, she is just choosing not to by being on her tour instead. Her choice. You're making it sound like some external force is stopping her from being there.
No, she's "not choosing" not to be there because of her tour. The tour was planned WAY before the awards were even mentioned. Katy doesn't need to go to every single award show everytime she gets nominated.
The Billboard awards are always the Sunday before Memorial Day weekend (Memorial Day is the last Monday in May, which falls on Monday, May 26 this year; the Sunday prior to that weekend is Sunday, May 18, 2014). I am sure Katy knew that, even if the date had not been officially announced. If she wanted to be at the awards show, she could have either taken a break from her tour, or planned her tour so that she'd be in or near Vegas that weekend. By choosing to be in the UK, she chose not to attend the Billboard awards. It was entirely her decision.
Oh for god's sake, would it have satisfied you if I took an over-PC approach and said 'shame Katy will not be there due to prior commitments?'. I can pretty much guarantee you that if she wins an award and they show a video message of her from the UK saying thank you she'll say something like 'I'm sorry I can't be there with you guys tonight, I'm on tour'.
And the tour in a way is an external force stopping her from being there. Yes, technically she could cancel the show and choose to go to the awards, but not really as she's kind of obliged to do the show that people have become excited about and planned going to for months and spent their hard-earned money on and she knows that. Just because there's technically nothing physically stopping her from being there, it doesn't make it wrong to say that she's not able to be there.
Are you aware that you just made a huge deal out of nothing?