The two examples I am thinking of right now are commercial spaces, which--over time--tend to get changed more often than residential but the process is the same, just accelerated.

A few blocks away is a building that has been a restaurant or bar for over 100 years. About 100 years ago the windows on the lower floor were bricked up to create a dark cellar-like appearance in the restaurant. Later, the block and neighborhood were rather dangerous and it became, in turn, a dive bar, then a gay bar, then more recently a lesbian bar, and now a gay bar again but with a very mixed patronage. The building went through a period of being even more closed-off (All the windows) and blending in--during a period where even setting foot in a bar that was considered to cater to a gay clientele could get you jailed, or at the very least fired--to a slightly more obvious presence, including a bright peach paint job, to most recently being covered with banners of model-like people to cover up the blankness.

Anyway, they recently reopened all the bricked up windows on the lower facade. The building is Italianate-eclectic, and they did put in the appropriate arch-topped windows (although cheap ones) and are doing a more period appropriate paint scheme on the pillared and arched concrete facade.

But the latest addition is very contemporary stacked stone below the arched windows in the embrasures between columns.

It's trendy,it coordinates with the new paint scheme, and they did a decent job putting it in, but I think it has nothing to do with the building and kind of cheapens the overall appearance. I would have spent that money on better windows and skipped the stone.

In my gym, which is a cobbled together complex of 7 buildings, I have seen the same sorts of transformations, from a 80s-90s Post-Modernist detailing, to a mix of Post Modern and De-constructionist, and now they are removing a lot of drywall and skewing raw and industrial.

In the meantime, the shower area in the locker room went from a green and white ceramic tile with black accents (which either could have been very old or from the Post-Modernist period) and now it is some vaguely Tuscany-modern thing with stone-look tile with stone accents and vessel sinks (with kitchen faucets,probably for budget).

I don't think the new locker rooms look Better, or look more Appropriate, even though they are trendy. Also, although I rarely use the locker room since I live nearby, the times I have used it, it has a kind of stinky, mildewy smell because the tile is so much harder to maintain than the old ceramic. I have noticed this in Houses with stone tile in the bathrooms when looking at real estate, The showers often have a moldy, mildewy smell. The old locker rooms were easier to scrub down.

And the vessel-sink area is always a mess.

So, I think a certain amount of trend chasing is repeating mistakes, just in a different way. Nobody appreciates seeing a 19th century building with a 1950s storefront tacked on the lowest floor, yet we do the same tacking on of current trends without much guilt.