I see lots of this due to Govt. contractors hiring and then laying people off. Job security is not what it once was and most everyone knows this.
It's really just business, although you don't want to burn bridges. Most everyone that has moved up, did it moving around and it's expected.
I would say you need to take the offer and move on. While you make take it personal, it's still business and jobs can be here today and gone tomorrow. Your current employer should understand and respect your decision.