Security of RSA Keys in OpenSSL
Mostly because when the command was created DES was the thing, and "no des" meant "don't encrypt".  Now the default is different:

$ openssl req -new -newkey rsa:1024 -keyout rsa.enc.p8 -out rsa.enc.p8.csr
Generating a 1024 bit RSA private key
...................................++++++
...........++++++
writing new private key to 'rsa.enc.p8'
Enter PEM pass phrase:
Verifying - Enter PEM pass phrase:
&lt;snip /&gt;

$ openssl asn1parse -i -dump &lt; rsa.enc.p8
    0:d=0  hl=4 l= 710 cons: SEQUENCE
    4:d=1  hl=2 l=  64 cons:  SEQUENCE
    6:d=2  hl=2 l=   9 prim:   OBJECT            :PBES2
   17:d=2  hl=2 l=  51 cons:   SEQUENCE
   19:d=3  hl=2 l=  27 cons:    SEQUENCE
   21:d=4  hl=2 l=   9 prim:     OBJECT            :PBKDF2
   32:d=4  hl=2 l=  14 cons:     SEQUENCE
   34:d=5  hl=2 l=   8 prim:      OCTET STRING
      0000 - e9 37 68 99 cb 9c 4f 10-                          .7h...O.
   44:d=5  hl=2 l=   2 prim:      INTEGER           :0800
   48:d=3  hl=2 l=  20 cons:    SEQUENCE
   50:d=4  hl=2 l=   8 prim:     OBJECT            :des-ede3-cbc
   60:d=4  hl=2 l=   8 prim:     OCTET STRING
      0000 - 16 ad ce 41 47 e8 ba 85-                          ...AG...
   70:d=1  hl=4 l= 640 prim:  OCTET STRING
&lt;snip /&gt;


The algorithm that it actually used was des-ede3-cbc, aka 3DES-CBC.  While AES has almost entirely supplanted 3DES, 3DES isn't considered insecure.

NIST SP 800-57 Revision 4, Table 2, says that 3DES has 112 bits of security, putting it on par with RSA 2048.  Table 4 then says that 112 bits of security is good through 2030.