First, lego no longer has a consistent color scheme, so only pieces from one genre go with other pieces of that genre.
Next, there's the proliferation of zany specialized parts. I remember getting a lego cargo ship as a kid (the hull was four specialized pieces — bow, stern, and two mid sections and thinking this was awful. Lego doesn't do ship sections any more but many similar things.
It's not a get off my lawn thing. I still love lego. But it does seem to have exchanged its DIY charm in the pursuit of merchandising.
That said, you can build much better looking models now — just not out of any reasonable selection of pieces.