They didn't unintentionally break security features; they knowingly did so - the potential for information disclosure was widely documented. In their defense - the solution isn't trivial in general, and large parts of at least spectre apply in ways a CPU would be hard pressed to prevent (how is a CPU to know that even though memory isn't marked as protected from currently running code in actual fact that's because the JIT and the JIT-tted code are running in the same memory space?). But the intel CPUs are leaking a lot more data than reasonable.