This doesn't work like you might think: first of all, the fees today are
greatly subsidized - the actual cost to store data in the blockchain is much
higher than most storage solutions. Secondly, only the miner receives the
fees, not the majority of nodes which have to bear the burden of the data.
That is, the fee system is setup as an antispam/deterrant, not as payment for
storage.
 
There's a difference between storing the content itself, and storing just a hash to content (which however is not spendable payment). I undertand why content itself doesn't belong. But it goes too far to say that only payments should be allowed. 

If the fees are not enough, fix the fee structure, don't stop incredibly innovative and promising uses of the distributed timestamping database. That is definitely throwing the baby out with the bathwater. If the issue is size, then address that, rather than the content itself. 

Have I misunderstood this discussion or are some proposing than nothing except payments be allowed?

Discriminating based on transaction content violates neutrality of the protocol and in my mind removes a very very large possibility of future innovation. If bitcoin is a platform and not just a payment system, then it needs to be neutral to content, like TCP/IP so that other protocols can be layered. Solve the size problem itself, without picking and chosing which uses of bitcoin are good and which are "bad" or "spam". I think it risks killing a tremendous amount of innovation just as it is starting.



Not the same thing at all; nobody is forced to store/relay video/voice/images
without reimbursement. On the other hand, any full Bitcoin node is required to
at least download the entire blockchain once. And the network as a whole
suffers if nodes decide to start not-storing parts of the blockchain they
don't want to deal with.

So don't store content, but allow hashes of content. 
Again, I think it is extreme and extremely restrictive to say that ONLY payments are allowed.  

 
This is how merged mining solves the problem. A single extra hash in the
coinbase can link the bitcoin blockchain up with unlimited other data.



Can you explain this part or refer me to some docs? What do you mean by "coinbase", I assume not the company. 


Thanks for the reply and explanation!