The difference between a max of warp 7.6 and warp 8 isn't slight, it's massive. It's the difference between being corralled by D6s or being able to simply flee. I'd also point out many of our speed limitations and quirks are due to our v3 nacelles and warp 8 cores, once we upgrade to v4 nacelles and w9 cores this thing'll be extremely fleet... If we don't lobotomize it's FTL system right now. It'll still likely be stuck at a reduced speed and won't be upgraded if it's got a truncated deflector.
Besides, we have the warp 7 Archer-class for transport and technical support, that design's dedicated for it. Why throw out a warp 8 heavy cruiser for a warp 7.5 slightly less capable, slightly more generalist, more heavily armed Archer-class?
We sacrificed a great deal so our warp 8 fleet can make the transition to warp 9 via refits and upgrades, it's time to fully exploit that advantage, think forward and design ships that'll hang around for a while, bulk up our fleet, give us a reserve of fast, tough, strong ships. We've got a breather to start building things that'll be here for a long time, may as well start now.
You don't have to yell.
As the OP has pointed out, Max warp doesn't reflect on interior emergency situations. A fast ship with bunch of guns is by definition generic and the most easily replaceable thing we'll have in our roster.
Also I attend to vote for linear or Sprint to claw back some of the tactical speed.