To answer the OP.
The independent economists need media exposure because that helps them get valuable speaking dates at conferences, consultancy and advisory jobs, and allows them to get their message out there. Thats why Rogers, Faber, Roubine, Rogoff et al all do media jobs.
Separately they may have a dual career in academia. (Take for example my personally preferred pundit, Niall Ferguson)
And the independents are far more responsive than the economists employed by the big banks, whose opinions are slow off the blocks, and invariably super bullish in support of their employer's sell side mandate..