Part of the issue is irreversible transaction.
It would be safer to build a decentralized platform on top of Bitcoin where Bitcoin transactions can be reversed if unauthorized people gain access to users coins
You don't know what you're talking about. This would mean that anybody could reverse his transactions for no good reason. The merchants would have no reason at all to use Bitcoin, actually, it would be the opposite: they would avoid it.
Well any credit card transactions can be easily reversed by the credit card company or bank, but most merchants still accept credit cards.
I have reversed a few credit card transactions myself by simply calling my bank and asking them to do it when I felt the merchant charged me inappropriately or failed to render services. Most of the time the bank will do it. The merchant is always given the chance to dispute the reversal.
Though I generally agree with bitcoin, transactions should probably not be possible to reverse. Or else you would need some person or persons to be the arbiter of any disputes and give them the power to reverse transactions. This would open a whole new can of worms.
If a dispute arises with a merchant that accepts bitcoin you simply can ask the merchant for a refund of your bitcoin. Failing that you can file a complaint with an authority or file a lawsuit.