I think perhaps there is an increasing tendency to design one UI for every platform (touch screen tablets, desktops etc.) and to favour consistency across platforms rather than proper integration within each platform. So if right-click is difficult to emulate on a touch screen, then often the desktop version of a program available for touch-screen devices won't make good use of right-click either.

It is perhaps part of a larger trend to try and solve UI problems for tablets and phones, then push the solutions back to the desktop, despite the fact the desktop didn't suffer from the problem they attempted to solve.