
I'm surprised none of the Summoners have brought this up yet:
In the SMN questline, you learn that the Immortal Flames keep a LIST of people who have defeated Ifrit without getting Tempered. (Because you know what happens to those who've been Tempered...) It's not a publicly available list, sure, but it exists. Conceivably, any of the people on that list could become a summoner, and it isn't a stretch for a PC to be on that list, especially for those with the Echo.
And just to echo (*cough*), the storyline also points at the Immortal Flames fighting a war of attrition against the Amal'jaa, who are constantly summoning Ifrit. The Ul'dahn primal situation is more unique because of the rich mineral deposits of Thanalan which allow the beastmen to keep conjuring their god with impunity.
With that in mind, it's easier for a Summoner to claim rights to Ifrit, but less plausible for one to claim Titan, who appears rarely, and Garuda, who is infinitely more cunning (and craycray).
EDIT: Oh, and OBVIOUSLY nobody is going to go and say, "I did it solo," because that's insanity. Everything I've stated above of course requires either an Immortal Flames task force or an elite adventurer group (which, in the canon, also exist in fairly high quantity).
In the SMN questline, you learn that the Immortal Flames keep a LIST of people who have defeated Ifrit without getting Tempered. (Because you know what happens to those who've been Tempered...) It's not a publicly available list, sure, but it exists. Conceivably, any of the people on that list could become a summoner, and it isn't a stretch for a PC to be on that list, especially for those with the Echo.
And just to echo (*cough*), the storyline also points at the Immortal Flames fighting a war of attrition against the Amal'jaa, who are constantly summoning Ifrit. The Ul'dahn primal situation is more unique because of the rich mineral deposits of Thanalan which allow the beastmen to keep conjuring their god with impunity.
With that in mind, it's easier for a Summoner to claim rights to Ifrit, but less plausible for one to claim Titan, who appears rarely, and Garuda, who is infinitely more cunning (and craycray).
EDIT: Oh, and OBVIOUSLY nobody is going to go and say, "I did it solo," because that's insanity. Everything I've stated above of course requires either an Immortal Flames task force or an elite adventurer group (which, in the canon, also exist in fairly high quantity).