They want all destinations to be equal
No - they want all internet connections to be paid for according to last-hop bandwidth to their endpoint and to
work according to the standardized protocols of the internet when sending/recieving data to other destinations from that link,
and for any other business related decisions concerning traffic to occur according to those same principles
Which is precisely the same thing as saying that traffic priority should not be dependent upon endpoint—i.e. that all destinations are treated equally—but with about forty-two extra words.
Firstly it's not about content delivery companies at all. It's about network operators, and network link pricing. Period.
Network operators are a pipe to content providers, so any definition of net neutrality that ignores the content providers is fundamentally missing the whole point of the network. The purpose of net neutrality is to ensure that your link provider cannot artificially distort traffic in a way that makes it impractical to use arbitrary services, forcing you to the services of their choosing. Manipulating network link pricing is just one mechanism for distorting traffic, and is quite possibly the least interesting, least effective way to do so.
And yes, when 'the tools at their disposal' include bandwidth tiering (free vs non-free) in an effort to distort end
user preferences towards their internet-based service, and thereby shift the fundamental usage of the
internet itself (away from free, open standards p2p protocols and towards proprietary 'walled-garden' services), this is, in fact,
not a neutral practice, and is in fact a problem.
Your argument is illogical. There is no difference between a content provider paying for the user's data usage and lowering the price of the content provider's service by enough money that the user can pay for a connection with a higher data cap on his or her own. Thus, paying for the user's usage does not violate any fundamentally sound concept of net neutrality in any meaningful way. Admittedly, in the case of Wikipedia, they're taking it one step farther and charging a negative fee for their service, which is a little odd, but if that's the way they want to spend their donations, so be it.
Now taken to the extreme—unusably low data caps combined with provider-paid exceptions—could potentially be a net neutrality issue, if only because it would be harmful to free content providers. However, that scenario is pretty darn unlikely. There are too many dozens of free, moderately high-traffic content providers for that to happen in the foreseeable future. If that changes—if all the world's websites consolidated themselves into just a handful of server farms—then it would make sense to reevaluate things. Unless and until that happens, however, it makes little sense to create laws in an attempt to prevent problems that are purely hypothetical. Doing so adds extra regulatory burden without solving actual problems, and worse, gives businesses more time to look for ways around those regulations, ensuring that by the time they are actually needed, they don't work.
And more importantly, none of the proposed solutions for net neutrality that I've seen would prevent this sort of "collect calling" anyway.