1. Grapes are almost always propagated clonally, through dormant hardwood. Only grape breeders really grow grapes from seed, and they're not using the seeds from open pollinated grapes like these, they're doing deliberate crosses from pollen. If you could grow out the seeds (hint: you can't, it's seedless) from this grape you would not get something all that similar to its parent, and only maybe 15% of them would even be perfect flowered and fruit bearing. This "EULA" doesn't seem to cover pollen, which I don't think would be legally enforceable anyways.
2. Non-propagation agreements and propagation fees are extremely common. Newer varieties of grapes almost always having a fee back to the breeder.
3. Nobody is making decent money breeding grapes. Most new varieties are from university research departments on constantly decreasing budgets. The propagation fees are typically there to help offset losses.
4. The only thing unusual I see here is printing this kind of label on the package and also the proscription against growing from seed. Not sure why they'd bother. Propagating grapes from a grocery store cluster would be extremely difficult. To get a clone from it you'd need to do labratory tissue culture. To grow from seed you'd need to find the one grape in thousands that freakishly actually produced a viable seed (this variety is seedless) -- cold stratify keep it in the fridge for months without it drying out or getting mold and then plant it out in the spring, and even if you planted hundreds you would be unlikely to get a vine worth bothering with.
EDIT: Also, let's say you actually legitimately wanted to grow or even breed with this vine, and you lived in the narrow climate range where it would succeed in growing. You could probably purchase dormant hardwood cuttings from a licensed nursery for less than $5 a vine. I don't think that's so odious. Or if you're a breeder you might even be able to coax another person with the same passion to mail you some pollen from it for free.
FURTHER EDIT: Part of what might be happening here is that these new table grapes are considered by some to be a bit of a major advancement. The cotton candy type flavours are novel and the nice crisp flesh is desirable, and I believe they have pretty good shelf life as well. So the breeders are trying to protect something that is a bit of a win for them. I imagine in California in particular there is a desire to avoid growers in the central valley from propagating these en-masse without license. I imagine that in about 10-15 years there'll be a bunch of new varieties similar to these out there and it won't be as big of a concern.