The headline is misleading: its "high share price", not "too big". Its perfectly possible for a small company to have a high share price.
Share prices can be much higher, Berkshire Hathaway has a price of 103,000
The main reason the Dow is used by the media, is because ignorant financial journalists think its the best measure - it is in their terms, where "best" means most brand recognition.
The only legitimate reason for using it is for long term comparisons: it has existed a lot longer than the S & P 500, or any properly constructed index.
Full explanation here http://moneyterms.co.uk/dow-jones/