We make a lot of money from subscriptions today. But when you are first starting out making money from advertising is super easy, taking all of several minutes to add to your site.
Getting set up for payments and running a subscription business is very complicated and takes a lot of time people and money. Time better spent perfecting your product early on.
If paypal had a mechanism to pre-validate, to avoid having 10's of 1000's of dollars frozen, then they'd be fine.
They get hate because their approach to post-hoc fraud limiting has fucked over thousands of people. Don't dismiss the hate, they earned that hate one customer at a time.