How does Gemini choose its altcoins? Are the altcoins they list worthy of consideration over non-listed coins? The list seems random to me...

Currently these are the only tradable coins on Gemini:

BTC
ETH
BCH
LTC

Alts Im familiar with:
LINK
ZEC
MANA
ZRX
KNC
FIL
STORJ
REN
UNI
YFI
AMP
AAVE
DAI

Alts I've never heard of:
PAXG
COMP
BAL
CRV
SNX
UMA
OXT
MKR