My DVR is two clicks. Hit record then choose single recorded or subscribe. Plus all the relevant subscribe options. This seems pretty reliable to me.
This effectively exists. It just isn't by hitting the Record button. Instead;
To set a single recording from the Theatre View Guide - Highlight the program and click OK, OK. (Or of course, one press of the Record Button.)
To create a subscription recording from the Theatre View Guide - Highlight the program and press OK, Right Arrow, OK.
So MC is currently capable of what your DVR does, since you would also need to scroll to at least one of the selections after hitting Record, while the other would just be a second click.
I'm not too sure about double click either. These type of things effect the learning curve.
Everything has a bit of a learning curve. I guess pressing the Record Button once to record is intuitive, but anything else isn't. That comes from the button name, and all the training people received in the days of VCRs. Yes, using your VCR has a steep learning curve. Remember Mum and Dad giving the remote to the kids to record something? Subscriptions weren't available on VCRs, so there needs to be a new standard set for intuitive. If WMC and DirectTV used two presses of the record button to create a subscription, then that is a good standard to use.
While there used to be some issues in detecting double presses with some equipment, I'm pretty sure that has been sorted out with modern, faster IR devices.
Anyway, I think Jim and Yaobing have spoken.