Gotta love the excuse
"We do have safeguards but we serve billions of ads so something might slip through"
"We can't be arsed to really ensure our users' security, so we just half-assed it and when it breaks, oopsie"
Computers do what they are told. If they are given the proper procedure to lock down incoming data, that procedure will be applied on ALL incoming data. Computers don't just skip something every now and then - not when they are properly programmed.
What Grindr is actually saying is that they cannot properly lock down ad security because they would be limiting the number of ads they can serve. Which, in turn, means that those ads are doing fishy things in great numbers, but Grindr prefers the revenue (duh).
Once again, consumers are left hanging in the wind in the eternal battle between money and security. And money wins every time.