I've been looking for a job. A few companies/recruiters have contacted me asking if would come in for an interview (
I didn't apply). I'm reasonably sure that I would not accept an offer from them (due to company size, the company's product/market, and/or the company's brand), even if they gave me one. On the other hand, some engineers I've spoken to have said that their initial judgment of a company was proven wrong or changed when they actually interviewed.
That being said, should I (ethically) take interviews just for 1) practice, 2) leverage with the companies I actually want, and/or 3) the possibility of being pleasantly surprised, or should I just decline and not waste their time?