JF-17 is good for Pakistan. Their requirement does not go beyond making it difficult for India to attack.
LCA, on the other hand has to ultimately blossom into a product that will insure India against foreign pressure in future. Remember what the Americans did to Iranian F-14 and France did to Argentine Exocet. The extraordinary degree to which India and China go to adapt foreign tech available off the shelf is because the suppliers cannot be relied upon on strategic issues. That is why DRDO in India and umpteen labs in China get such strong support from their respective governments. At times even tactical level help is not enough so again a detailed growth path needs to be framed in advance. LCA kind of programs are meant for this kind of path. Something that is not expected off JF-17.
Pakistan does not have these 'trust' issues. It can simply latch on to US or China or whoever wants to negotiate with India. They will not let Pakistan falter.