It could mean different things I guess, but here’s my take:
If you do very risky R&D in a big corpo then the risk creeps into other things: other projects might look at the R&D and say, “we will just use that when it’s done”. It’s a lazy kind of move for tech leaders to make, because it makes you look like a team player, and if the R&D goes belly up then you have someone else to blame. This ultimately leads to risky R&D in a big corpo not being compartmentalized as much as it should be. If it fails, it fails super hard with lots of fallout.
But risky R&D at a startup is compartmentalized. Nobody will say they use the output of the startup until there are signs of life, and even then healthy caution is applied.