Because this is a massive barrier to entry for Europeans. You either need to essentially be a lawyer or you can't run ads (or you break the law). Non-europeans can easily implement ads and combine this with in app purchases and what not. Europeans can't do that nearly as easily. They will get out competed. I don't see how you don't see how this is bad.
European here, both a consumer and micro-ISV owner.
As a consumer, I very much like the protections the GDPR provides.
As a business owner, I don't find GDPR to be a barrier to entry - TBH, anyone who actually cares about user privacy at all would have been near-compliant even before GDPR name in. For me, I think it was 1-2 days, most of it spent reading.
It's not difficult to comply with, and I'd be very against exemptions for small businesses - also because larger businesses would use it as a loophole to game the system.
You very much don't need to "essentially be a lawyer" to be able to include ads - services like AdMob have easily configurable SDKs for getting GDPR-compliant consent.
It's really no more than a few lines of code to respect user's privacy, and if you're collecting significantly more user data then you should be handling it with care.
I'm sorry but this is utter rubbish. The GDPR is easy to follow. If you can't think 9f how to run a business without being reckless or scummy, then you shouldn't be running one.
I work in the EU, in tech, with customer data, with these rules and have zero problems following them.