(1) Proximity to hotels
(2) Proximity to public transportation
(3) More centrally located for other uses (concerts, conventions, etc.) which should be a big priority if it is getting public funds
(4) Could have one multi use facility for the Bills and Sabres
Really it all just boils down to accessibility. Having it downtown makes it more accessible to more people. Which, if you're asking for oodles of public dollars, should be the goal.
Buffalo fans often complain about Buffalo not being treated like a real city. Well, connecting a major infrastructure expenditure like this to the existing public transportation network would be a nice start. Run a subway out to orchard park and then I'll start thinking of that location as anything but a bad joke.
I think the problem is... they studied what kind of events are realistic and what kind of revenue they would provide. They also studied the amount of land acquisition, infrastructure, permitting, etc would be required downtown. The delta between that did not come anywhere near close to making it worthwhile for a few monster truck rallies. We arent landing a superbowl. Probably not a final 4. No wrestlemania. No marquee NCAA bowl games (the 3rd or 4th rate bowl game they can attract or the MAC title would be sparsely attended). No regular NCAA neutral site games.
We are probably talking about doubling the cost for the stadium. Instead of asking the public for perhaps $700 million, you would need to ask for $2 billion. Have you tried leaving a Sabres game parked in a ramp or close to the arena during a playoff game that comes down to the wire? Multiply that by a factor of 3. "Building a subway" isnt feasible either Buffalo isn't nearly as big of a population base as the 1st and 2nd ring suburbs. That is a huge cost for Bills games?
A new stadium would likely land the same amount of concerts and events as the existing one. Many winter concerts and events in a city this size can take place at the arena. Ideally, we can land a brick and mortar amphitheater somewhere downtown in the outer harbor or something. That would accomplish what everyone dreams a football stadium would. 10K-30K people downtown for many dates all summer. Put Darien Lake (concerts) out of business.
Ultimately a stadium helps downtown not at all, and people would argue it would hinder it. What we really need down there are 1-3+ Fortune 500 companies headquartering there. Then, people will live down there, property values skyrocket, commerce happens, and suddenly the cranes all come in.
Orchard Park is fine for the Bills. NFL games are typically all-day events and an extra 15 minutes for Canadians and Northtowners is not a factor, especially when most people arrive before 10AM. Its wide open, traffic isnt exactly perfect, but it is tolerable. All the lots and infrastructure/facilities already there, county-owned land.
What is interesting here though is the apparent abandonment or lack of an ask for the arena. The arena is well overdue for some moderate renovations.