NetworkCoin would be a really, really nice name for the coin, as good as, or better in many ways. Netcoin is still good, yes, that's awesome, but to match the coin to the name of the domain is very important.
In the real, brick and mortar world, if I said, "I'll give you dollarines for that", well sure, that's real close ... but marketing and branding really demand that if you CAN match the name of your DOMAIN to your, (product-coin), it's a very good thing. To compete in the SEO namespace of "network" would be very nice as well, a doable challenge.
Many people, when trading real value, and taking real risk, having to make a decision IF "netcoin"="networkcoin"="NTC" ... well why take that risk ... at all?
I agree that it is important that the names match. The final audience will not be just a couple hundred crypto fans who would support it even if the domain is different from the coin name. It needs to appeal to a large audience, and having naming congruency will only contribute to that, no matter what the name is.