The real problem behind Steam/Rivatuner Incompatibility...

Translation: you're butthurt that Valve isn't designing Steam to accommodate 3rd party software overlays, so you broke MSI Afterburner to prove a point, gambling that users would blame Valve instead of blaming you.

I understand why you're frustrated, but you became the ******* instead of the solution is when you took your issues out on the users instead of focusing that energy into resolving the problem with Valve. At this stage, they're more likely to contact MSI and ask them to pull your funding than contact Valve and ask them to change the way the Steam overlay works.

The second-to-last sentence above is a example of where you've misjudged the importance of MSI Afterburner. Based on a quick poll of about 30 online friends, nobody wants (or needs) to see diagnostic data during games' splash screens and menus. It's not relevant until you're loaded into the game. Idle temperatures, idle clocks, and idle voltages are just... pfft. They're not useful performance metrics. Instead of being useful, MSI Afterburner is simply annoying or distracting at these times.

There was actually a good idea that came out of my impromptu poll: instead of implementing a fixed time delay, we'd recommend an option to trigger the overlay when the GPU switches to 3D clockspeeds. If you wanted to get fancy, you could enable displays when parameters such as CPU load, GPU load, core clock frequency, power, or temperature exceeded user-defined thresholds, so that the amount of data displayed by Rivatuner is proportional to system performance margins.