Yes, I can surely understand. It's the same with SPayLater with Shopee. The buyer happily purchase items on Shopee with reduced monthly payments but when the bill suddenly comes for combined purchases, it may be too much for some as it's easy to just click, click, click on items to buy things. 

I don't use SPayLater on Shopee anymore as it's troublesome, not so much I don't have enough cash to buy things. For the most recent purchase via Atome, I could actually pay in full amount but chose the 3 payment plan since it's a one-off purchase which is more than RM5k. There is basically no risk since the payment via Atome is auto-debit with credit card so there won't be any late charges.