You should never, ever use a PRNG (pseudorandom number generator) when you are creating a wallet seed phrase, private key, or extended private key. Here is why:
PRNGs use a deterministic sequence to generate the numbers. Most PRNGs are seeded with a combination of process ID and the current date/time in unix timestamp format. Some are even worse and just leave the seed at zero or some other constant. This is very bad for security because it means attackers can guess the key from a limited number of inputs. So instead of 2^256 guesses as it's supposed to be, you're now looking at something like 86400 (in case you only know the day) times 3,000,000 (on Linux process IDs can get really large for long-running systems, on shorter-uptime systems or on Windows they can be even smaller) times like 5 or 10 in case the RNG was called that many times.
As you can see, this is easily calculated on a GPU, and will result in stolen funds once the private key is discovered.