So, I think at this point it's not warranted to force people into ranked PvP if they want to actually achieve something in a meaningful time in this horizontal progression MMORPG.
In theory usually you will reward people the highest honors for doing ranked PvP in other games with gear/titles etc only achievable for the best of the best which is PARTLY true in GW2 and I wouldn't even complain if it weren't for the fact that you can literally afk-bot in ranked and still get the same rewards as somebody who's in the highest possible division albeit slower.
Meanwhile for doing unranked sPvP (I enjoy stronghold which doesn't even exist in ranked for some reason) you ONLY get the reward track and miss out on a kitten ton of gold and ascended gear through the ranked only chest.
Usually I wouldn't complain about this BUT why do I get rewarded more in WvW for escorting dolyaks than for playing unranked PvP?
Because unranked PvP would be even LESS popular when unranked gives the same reward?
Then the issue would be people not wanting to play ranked in the first place so in my eyes that is not even an issue, if the mode is ONLY fun because it's rewarded more then either merge the 2 modes or be okay with only playing against other likeminded people, some would probably even see this as a positive if bots/people like me who only play ranked for the legendaries disappeared.
TLDR; There's no reason aside from incentivizing people who don't want to play ranked in the first place to have unranked PvP not provide the rewards that ranked gives (aside from titles/tournament rewards etc) in a game where you can literally afk or play 1-5fps metatrains and get 10x higher rewards from that.
Give unranked PvP the reward chest