It's because EPA under Obama changed emissions regulations from average across vehicles sold to tables by wheelbase (in order to try and tighten mpg on larger vehicles instead of sedans just getting better to average it out). So now, as MPG requirements go up, they just build bigger cars to bump into the next size instead of hitting MPG targets for the current size. This is also partly why there's few sedan models and everyone has just moved to crossovers.

Every potential regulation/deregulation has unintended consequences that should be explored to figure out if the consequences may be worse than current. Instead everyone just does it by throwing darts and assuming everyone will just go along with the intent. When that doesn't work, they go about blaming the other side for loopholes before repeating the process to try and close those loopholes up.