It comes down to a decision of the operating airline. Stairs are not free and add weight to the airplane. So it's a business decision depending on the intended use. Think it's the same with the Embraer.
Yago From Iceland, joined May 2002, 232 posts, RR: 0 Reply 3, posted (8 years 3 weeks 13 hours ago) and read 1257 times:
I thought all Embraer 170 carried the stairs, if they don't then what you both say make sense.
When I was dispatching flights for Air Littoral in Nice, we had some Fokker 70 and when they were parked in gates it was a pain because we had to install the fingers and it did reduce dramatically the rotation time.