Maybe it was advanced for the time being created, to me it's just any other RFID card that is issued everywhere else in the world in the matter of read speed, from every public transit card that I find in every EU country I've visited (maybe for a US citizen not used to public transit it seems something special, I don't know), to skipasses, to even your gym card.
Having the option to also pay with credit card would be much more convenient to tourists, when I visited Japan I've had difficulties finding the right place to get a SUICA card (being that my Android phone didn't have Felica chip, as most phones sold outside Japan), and on top of that you almost everywhere need to charge it with only cash. And you can charge it only by 500 or 1000 yen at the time (depending on the machine), and of course tickets always have not round prices like 110 yen. And you have 500 yen of deposit for a card that probably costs to them 10 yen to manufacturer, unless you get the red SUICA card that you can get only in some special machines at the airport but with that you don't get back the unused credit when you leave (you can spend it at vending machine tough).
So the speed saving of a couple of ms of not having to pay by tapping your normal credit card is completely vanished by wasting time to charge that card.
BTW even if they don't want to put credit card POS on every station (I get it, it's expensive and they need to pay fees if someone uses a card, compared to cash) they could make a system that uses regular NFC (would be 100ms slower, who cares) at least for tourists so they can use it with a regular NFC card in their phone wallet that they can charge with an app without requiring a technology that only works in phone sold in Japan?