#1) There are a ton of coins that have low block times. They do it to make fast confirmations. Who wants to wait 50 minutes for a confirmation? Or even 10?
Apparently a lot of people. Ask yourself this: Why are these fast blockchains not being used?
Take litecoin or dogecoin.
Litecoin exists for, what? 6 years? It's a well established coin with over 2bn in marketcap (what bitcoin used to be a few years ago). It's not very volatile so it's not like its value will plummet by the time you broadcast the tx and the time the receiver gets the money. Yet it has very few txs - despite the lure of virtually zero fees (it has plenty of transactional capacity)...
Litecoin last transactions:
Recent Blocks
Height Age Transactions Total Sent Total Fees Block Size (in bytes)
1262932 12 seconds ago 1 0.0 LTC 0.0 LTC 322
1262931 14 seconds ago 13 7,183.193 LTC 0.114 LTC 4,448
1262930 a minute ago 26 29,050.847 LTC 0.368 LTC 8,650
1262929 2 minutes ago 5 16.614 LTC 0.001 LTC 1,198
1262928 2 minutes ago 1 0.0 LTC 0.0 LTC 327
Why do you think people prefer the slow bitcoin and there is so limited transactional demand spillover to altcoins for faster transactions?