That is a naive statement - this is 2nd biggest crypto-currency network.

Any network that suffers a 51% attack will require a remedial fork to clear up the mess - so you've not really research your opposition to forks, because they are compulsory in certain situations.

From what Vitalik Buterin published 15 hours ago, he listed costings at:

1% issuance equals $50 million costing on the remedial fork

0% issuance equals $5 million costing on the remedial fork.

From these costings for Ethereum Network at the current market valuation $700 million the Ethereum community will probably choose an issuance below 0.5% to minimise the security theoretical costings.

This annual increase of coinage, will be below 45,000 Eth. As opposed to the current production of 12 million Eth.

Then, there is the current electricity bill for the entire Ethereum Network that can be costed at $0.10 at eye-watering amount of $28 million!

Ouch

This is being funded by investors and miners who are accumulating Ethereum.

Annual production at issuance 0.5% equals $360,000 of costings, assuming these are sold off by investors.

Nearly all of metrics say: the investors in Ethereum are going too have plenty of spare cash through the $28 million saving on electricity too achieve a higher price than the current POW price.

Yelp, the Casper POS is a win and win situation for the Ethereum Network and investors - no-one who does the Maths is going to say a saving of $27.6 million is going to cause falling market prices.

Finally, there are a whole sweep of businesses under development expecting to be deployed in 2017 and 2018, which will further increase the market price of Ethereum.