I agree TCP slow start is crucial part of the control mechanisms that exist in networking. Unfortunately these protocols have not kept up with the wireless revolution. This feature leads to bandwidth oscillation and buffer starvation in mobile data networks like WCDMA/HSPA and LTE.
Some optimisation of this protocol was started a while ago by Nortel prior to its breakup but I'm unaware of any further work.
It would benefit a large number of people if some smart TCP hacker could find a way to meet the congestion control required to keep our internetwork links running and at the same time optimise the wireless experience.