You are completely right for things that don't involve real-time video (like games do).
A 1/60 frame skip rate sounds like nothing important, but your eye will see it easily and it's instantly annoying. It's not subtle at all, and not something you can write off. Everyone will be annoyed by it and then your product will be doomed.
(Edit) I do however agree that the frame rate is not that important. 30 fps ought to be enough for anyone. However, it has to be a really really smooth 30 fps; all the frames need to come out exactly 1/30 of a second apart. Not realizing this is where a lot of people go wrong. A smooth 30 fps looks much better than 120 fps to a human eye. A game framerate that isn't an integer divisor of your monitor's refresh rate is also a disaster (since it means the display will be skipping frames).
If it's the difference between shipping and not shipping, ship, of course. But you propose a false dichotomy; the OP can both ship C++ code and avoid frame skipping.
Speaking as an avid gamer, that dropped frame matters, a lot. It's incredibly annoying to the gamer, and will produce an attitude of general discontent with the product that will earn it reviews like "sluggish", "slow", "unoptimized", and "chunky", none of which are exactly going to help you sell copies.
You might have missed the part where the author was saying that he wasn't even nearly done with feature implementation; the problem was only going to get worse as he added more garbage overhead. When you're talking about relatively expensive GC passes in a stop-the-world garbage collector, that dropped frame can turn into 150 dropped frames every 30 seconds pretty quickly (ie, a 2.5-second freeze/hitch), and that's enough to turn any player batty.
A 1/60 frame skip rate sounds like nothing important, but your eye will see it easily and it's instantly annoying. It's not subtle at all, and not something you can write off. Everyone will be annoyed by it and then your product will be doomed.
(Edit) I do however agree that the frame rate is not that important. 30 fps ought to be enough for anyone. However, it has to be a really really smooth 30 fps; all the frames need to come out exactly 1/30 of a second apart. Not realizing this is where a lot of people go wrong. A smooth 30 fps looks much better than 120 fps to a human eye. A game framerate that isn't an integer divisor of your monitor's refresh rate is also a disaster (since it means the display will be skipping frames).