Recent breakthroughs in quantum computing?

Can anyone explain to me why we have had no major breakthroughs in the theory of quantum computation in the past 15 years?

Shor's algorithm set the standard, since then we've had Grover's algorithm and an improvement on the Deutsch–Jozsa algorithm. What quantum algorithms of practical value have been created since Grover's?

What makes it so hard to create a quantum algorithm?

Thanks.