Yep, but I think that issue is often grossly overstated. A weak specialist will get up to speed more quickly, but will be a long-term drag on productivity; a strong generalist will need more ramp-up, but in the long haul will be much more useful.

Or to rephrase that in practical terms: hire specialists as contractors, and generalists as employees. Not always -- there are certainly exceptions, especially if your business has particular specialty needs -- but more often than not, that's the right tradeoff...