Actually the menu says "No services apply". But in CS 5.5 the whole menu is there.
I think the Macintosh Services menu was probably disabled when InDesign was re-written for Cocoa and 64-bit in InDesign CC. But, for me, options under the Services menu rarely worked in earlier versions of InDesign. I'm sorry you're losing some functionality. Since I'm not familiar with LaTeXIt, I can't suggest a workaround. What were you using it for?
I did a little more testing. It's hit or miss which applications respect the Services menu. It seems to work best in Apple applications like Safari, Mail, etc. but less so elsewhere. Applications that handle their own text like Adobe applications mostly ignore it.
I use LaTeXIt to format mathematic formulas in technical publications. Under CS 5.5 the services installed by LaTeXIt became available as soon as text was selected and the formula was automatically formatted and inserted into my document. Now this convenience has been lost and I require a much more time consuming process of creating the formulae individually and importing and placing them manually. Hadn't done any technical work since getting CC but now I need it. As you say it looks like CC ignores the services menu altogether. Grrr.