No use supporting a coin that are not accepted for payment everywhere.
thats what matters most.. many people think its about price.. long term its about what bitpay / coinbase offer as the coin thats acceptable to their merchant tools/shopping cart API
as for the exchanges.. pretty much all the coins will be on all the exchanges
You are making contradictory statements (as always)
It is no use supporting the coin which doesn't get traded (read listed) at major exchanges (and Coinbase is nowhere near being one). If we compare the impact of exchanges versus merchants on Bitcoin price, the latter will suck heavily as you yourself say ("pretty much all the coins will be on all the exchanges"). It should be obvious that most of Bitcoin value comes via exchanges, so Coinbase, Bitpay (or any other payment processor, for that matter) with their shopping cart API's will be utterly irrelevant if exchanges refuse to support a certain coin
im not being contradictory at all, i just see things layers/dimensions deeper than most
as always you think 'value' means price
but value is utility
anyone can have a coin with a large market cap
anyone can cause a swing in the price
but if you went to use bitcoin to buy something real.. and found out that the merchant tools (shopping cart) was using a different chain.. then your stuck with a coin that cant buy real things.
..
as for the exchanges, most exchanges will offer swaps between the different chains.. thats where exchanges get their profits. from people doing swaps
..
ok lets simplify it for many people
instead of thinking about price of bscoin(segwit) bitcoin(legacy/classic) bitmaincoin(bitmains alt) and the fight for price.
imagine coinbase, bitpay, purse, gyft and other real world purchase utility flipped to use litecoin for real world goods purchasing
now imagine the impact of merchant services deciding a certain coin for utility.. and let that play into your scenarios.. knowing it has nothing to do with which 'bitcoin' has biggest price..
once you do that and come to that realisation.. and ran a few cause/affect scenario's... simply replace the word litecoin for any of the bitcoin upcoming forks.. and realise the same applies. its not due to 'price' but due to utility and decisions of services