That's more often true for recent changes.
Look at the changes in Wolverine's costumes throughout the years:
http://geekologie.com/2013/07/the-co...erines-cos.php
Most costume changes are just pallet swaps, not modernized looks. And it's no coincidence that the looks which are modernized are more recent and look a lot less superhero-y and in my opinion less dynamic. Takes away a lot of the superhero aspects. Some are straight up boring and others are just movie adaptations. Where's the creativity in those? If Marvel as a whole is heading towards a more modernized creative direction, wouldn't more costumes start to have share similarities? More pouches, pockets, zippers etc. Is that necessarily creative? It became a notorious joke during the 90s.
As insincere as it might seem to you, there's some merit to it. Superheroes aren't real. Why should their costumes be grounded in realism? There's a standard in real society that doesn't apply to superheroes because they live in a fantasy world. I'm guessing police officers and fire fighters don't have the luxury of wearing superhero costumes because they don't have steel skin, healing factors, ultimate fighting ability, crazy reflexes, super strength etc.
More often than not, that issue is addressed within the book. He is constantly taking off his coat during fights and rolling up his sleeves. I feel like it's one of the most realistic portrayals of a modern costume in regards to practicality right now.
I'm trying to say modernized outfits, more often than not, look less superhero-y than their predecessors. Compare Bucky's facemask to his domino mask. One is practical. One isn't. One says superspy. The other says superhero. Arguably, he's both, but I feel like the looks should reflect superhero aspects more than their roles. Maybe that's just my preference. I find it more creative and dynamic than just going with what is expected. I do believe there's a balance, but it's my opinion that recent redesigns are having a hard time finding it.
In Hawkeye's case, he went from costumed vigilante to superspy. There used to be a time where he could stand with Cap, Thor and Iron Man and actually look like he fits in. Now, not so much. He looks like your standard SHIELD agent with a bow. It's boring as all hell. He doesn't look like a superhero at all anymore.