Each set of the Season Heroes currently only comes round once a year. The least frequent of all sets of event heroes. (Challenge Event heroes come round 2-3 times a year and Atlantis opens monthly).
The Seasonal Summon gate also shares the worst odds in the game (along with Epic Hero gate) so there is room add to out-of-season Seasonal Heroes to the gate without reducing the chances of pulling that Season’s Featured Heroes and bring the summoning odds for the gate in general more inline with Challenge Event and Atlantis summons gate.
More opportunities each year for F2P and C2P players to get Sand Empire or Halloween heal reduction heroes could help to reduce the number of monthly Field Aid complaints.
Whilst I would classify myself on the more spendy end of the spectrum I reckon I’m not the only one who knowing the poorer odds sees the gate currently as representing a poor opportunity-cost versus Event and Atlantis gate to not spend anything other than EHT on this gate. (I’ve not done badly myself with the strategy having bagged both Mother North and Santa with just EHT).
Whilst the rough concept image above isn’t my best work it represents the idea good enough though should note I just thought up the numbers for pull odds to roughly match Event/Atlantis 3/4/5 and event/non-event hero splits whilst being relatively easy to add up. Naturally actual values would vary.
In summary I reckon players from all ends of the F2P-P2W spectrum would benefit from more opportunities to pull certain heroes during the year (and especially players joining part way through a year) and events can retain the special nature of the in-season heroes by using the boosted rate Featured hero mechanic re-used from Atlantis gates. Also by making the gate’s summoning odds as good as the other gates and making it a more attractive option I reckon SG would benefit too from increasing spending.