Do people sign my subkey?
See this explanation. The 0x10 signature (typically belonging to a different individual) is applied to one's master/primary key, not to 0x18 subkey signature packets used for signing, encrypting, and authenticating.
Remember, CA responsibilities are decentralized with the PGP Web of Trust and the one's master/primary key can be used to sign other people's master/primary keys that also act as a reputation. By signing other people's master key(s), those people can revoke and re-issue subkeys as needed (with their reputation) without the involvement of those that have applied 0x10 signatures.
With more recent gpg code, the signing subkey will have a 0x19 backsignature when created.